README.md

TODO CRUD App in Rails

This is a simple Rails App for a TODO list. This app uses the following technologies:

• Ruby 2.2
• Rails 4.2
• PostgreSQL 9.4
• Twitter Bootstrap 3.3
• SASS 3.4
• bootstrap-generators 3.3

We begin by building a simple Rails TODO app that uses SASS and Twitter Bootstrap for styling, and then add Authentication, Session Management, and Authorization. For educational purposes we are not using a 3rd party authentication library but we instead will build our own authentication and authorization as we go. For those who would like to investigate a 3rd party library for authentication and authorization, I recommend taking a look at Devise.

The steps below will demonstrate how to create this project from scratch:

• Step 1 - Generate The Project
• Step 2 - Add Gems
• Step 3 - Configure Scaffold Generator
• Step 4 - Configure the Project for SASS and Bootstrap
• Step 5 - Create a Static Pages Controller and Views, the NavBar, and the Flash Messages Support
• Step 6 - Add MVC CRUD for the TODOs
• Intermission
• Step 7 - Add MVC CRUD for User
• Step 8 - Create a Sessions Controller
• Step 9 - Add a Nice Bootswatch Theme
• Bonus LAB Material
• Step 10 - Patch Security Holes
• Step 11 - Deploy to Heroku
• Helpful Heroku Commands

Steps to reproduce

Step 1 - Generate The Project

1a. Generate a new Rails project and initialize the GIT repo:

Note that the rails new command will create a new subdirectory for you.

rails new --database=postgresql --skip-test-unit todo_app_auth
cd todo_app_auth
rake db:create
git init
git add -A
git commit -m "Created Rails project."
git tag step1

Step 2 - Add Gems

In this step we add some nice gems to help us with Rails development:

• bootstrap-generators - adds Twitter Bootstrap styling to our rails generated views, see further discussion in Step 3 below.
• pry-rails - causes rails console to open pry instead of irb
• better_errors - provides improved Rails error pages

2a. Edit the Gemfile and add the following gems:

gem 'bootstrap-generators', '~> 3.3.4'

gem 'bcrypt', '~> 3.1.7'                # uncomment this line

group :development, :test do
  # Use pry with Rails console
  gem 'pry-rails'

  # Better Rails Error Pages
  gem 'better_errors'
end

2b. Commit your changes:

bundle install
git add -A
git commit -m "Added gems."
git tag step2

Step 3 - Configure Scaffold Generator

For this project we will be using rails generators to scaffold some of our MVC code. We will also be using the SASS/SCSS version of Twitter Bootstrap for styling.

Unfortunately, the out-of-the-box rails generators produce views that are not easily compatible with Twitter Bootstrap. So we need to customize the generators to produce view code that contains Bootstrap styling. Fortunately there exist a gem called bootstrap-generators that will assist us in this task.

3a. Install the custom templates:

rails generate bootstrap:install -f

3b. Add the following to config/application.rb:

module TodoApp
  class Application < Rails::Application

    config.generators do |g|
      g.orm             :active_record
      g.template_engine :erb
    end

3c. Commit your changes:

git add -A
git commit -m "Configured custom templates for Scaffolding"
git tag step3

Step 4 - Configure the Project for SASS and Bootstrap

We will be using SASSy CSS (SCSS) for our styling and importing the Twitter Bootstrap SCSS files into our main application.css.scss file.

The bootstrap:install command from Step 3 created the files bootstrap-generators.scss and bootstrap-variables.scss. We will be removing bootstrap-generators.scss and putting that code in our application.css.scss file. We will also rename bootstrap-variables.scss to add an '_' prefix to the name to signify that it is a SASS partial file.

We will also create the file _bootstrap-custom-variables.scss to hold any custom Bootstrap variables assignments we may want to define.

4a. Rename the application.css file to application.css.scss, remove app/assets/stylesheets/bootstrap-generators.scss and rename app/assets/stylesheets/bootstrap-variables.scss:

mv app/assets/stylesheets/application.css app/assets/stylesheets/application.css.scss
rm app/assets/stylesheets/bootstrap-generators.scss
mv app/assets/stylesheets/bootstrap-variables.scss app/assets/stylesheets/_bootstrap-variables.scss

4b. Remove everything from application.css.scss and replace it with the following:

// "bootstrap-sprockets" must be imported before "bootstrap" for the icon fonts to work.
@import "bootstrap-variables.scss";
@import "bootstrap-custom-variables.scss";
@import "bootstrap-sprockets.scss";
@import "bootstrap.scss";

body {
  padding-top: $navbar-height + 10px;
}

.page-header {
  a.btn {
    float: right;
  }

  a.btn + a.btn {
    margin-right: 8px;
  }
}

input[type="radio"], input[type="checkbox"] {
  width: initial;
  height: initial;
  margin-top: 7px;
}

main {
  margin: 20px auto;
  width: 800px;
}

.todos {
  th, td {
    text-align:center
  }
}

4c. Create the file app/assets/stylesheets/_bootstrap-custom-variables.scss with the following content:

// custom settings for Twitter Bootstrap
$body-bg: #4af;

4d. Commit your changes:

git add -A
git commit -m "Configured for Bootstrap SASS"
git tag step4

Step 5 - Create a Static Pages Controller and Views, the NavBar, and the Flash Messages Support

We will generate a static-pages-controller and its related views that define two static pages: a home page and an about page. We will also move the navbar that was generated in Step 2 via the rails generate bootstrap:install -f command into a separate html partial file along with creating a partial file to hold just the navbar links. Finally we will create a messages html partial file for styling the Rails generated flash messages / alerts that indicate when an action was successful or failed.

5a. Generate the static-pages-controller and its related views:

rails g controller static_pages home about

5b. Edit config/routes.rb and replace the static_pages routes with the following:

  root to: 'static_pages#home'
  match '/about', to: 'static_pages#about', via: 'get'

5c. Edit app/views/static_pages/home.html.erb and replace the content with:

<% provide(:title, 'Home') %>
<div class="text-center jumbotron">
  <h1>Welcome to the TODO App</h1>
  <h3>This is the home page for the Rails TODO App with AuthN and AuthZ.</h3>
  <br/>
</div>

5d. Edit app/views/static_pages/about.html.erb and replace the content with:

<% provide(:title, 'About') %>
<h2>A Simple TODO App with User Authentication</h2>
<h4>Technologies include:</h4>
<ul>
  <li><a href="https://www.ruby-lang.org/">Ruby 2.2</a></li>
  <li><a href="http://rubyonrails.org/">Rails 4.2</a></li>
  <li><a href="http://www.postgresql.org/">PostgreSQL 9.4</a></li>
  <li><a href="http://getbootstrap.com/">Twitter Bootstrap 3.3</a></li>
  <li><a href="http://sass-lang.com/">SASS 3.4</a></li>
  <li><a href="https://github.com/decioferreira/bootstrap-generators">bootstrap-generators 3.3</a></li>
</ul>

5e. Edit app/views/layouts/application.html.erb to set a dynamic title and replace the body with that provided below:

    <title><%= full_title(yield(:title)) %></title>

  <body>
    <header>
      <%= render 'layouts/navigation' %>
    </header>
    <main role="main" class="container-fluid">
       <%= render 'layouts/messages' %>
       <%= yield %>
    </main>
  </body>

5f. Create the file app/views/layouts/_navigation.html.erb with the following content:

<%# navigation styled for Bootstrap 3.0 %>
<nav class="navbar navbar-default navbar-fixed-top">
  <div class="container">
    <div class="navbar-header">
      <button type="button" class="navbar-toggle" data-toggle="collapse" data-target=".navbar-collapse">
        <span class="sr-only">Toggle navigation</span>
        <span class="icon-bar"></span>
        <span class="icon-bar"></span>
        <span class="icon-bar"></span>
      </button>
      <%= link_to 'Home', root_path, class: 'navbar-brand' %>
    </div>
    <div class="collapse navbar-collapse">
      <ul class="nav navbar-nav navbar-right">
        <%= render 'layouts/navigation_links' %>
      </ul>
    </div>
  </div>
</nav>

5g. Create the file app/views/layouts/_navigation_links.html.erb with the following content:

<li><%= link_to 'About', '/about' %></li>

5h. Create the file app/views/layouts/_messages.html.erb:

<%# Rails flash messages styled for Bootstrap 3.0 %>
<% flash.each do |name, msg| %>
  <% if msg.is_a?(String) %>
    <div class="alert alert-<%= name.to_s == 'notice' ? 'success' : 'danger' %>">
      <button type="button" class="close" data-dismiss="alert" aria-hidden="true">&times;</button>
      <%= content_tag :div, msg, :id => "flash_#{name}" %>
    </div>
  <% end %>
<% end %>

5i. Edit the file app/helpers/application_helper.rb and set the content to:

module ApplicationHelper
  # Returns the full title on a per-page basis.
  def full_title(page_title)
    base_title = "TODOs"
    if page_title.empty?
      base_title
    else
      "#{base_title} | #{page_title}"
    end
  end
end

5j. Commit your changes:

git add -A
git commit -m "Added static pages, navbar, and flash messages."
git tag step5

Step 6 - Add MVC CRUD for the TODOs

We are finally ready to generate the MVC CRUD code for our TODOs list.

6a. Generate the MVC CRUD for TODOs:

rails g scaffold todo title:string completed:boolean

6b. Edit db/migrate/<migration_script_name> and add null: false to the title and completed columns, for instance:

      t.string :title, null: false
      t.boolean :completed, null: false

6c. Run the migration:

rake db:migrate

Inspect the config/routes.rb file. A single line was added to configure the 7 routes for our TODOs resource. That's nice!!!

6d. Edit app/models/todo.rb and add the following:

class Todo < ActiveRecord::Base
  validates :title, presence: true

  before_save :default_values

  private

  def default_values
    self.completed ||= false
    nil                           # required so that TX will not rollback!!!
  end
end

6e. Edit app/views/layouts/_navigation_links.html.erb and add a link to our todos view:

  <li><%= link_to 'TODOs', todos_path %></li>

6f. Edit app/views/todos/index.html.erb and

• edit the <h1> tag
• add a todos CSS class to the outer div
• add the Show, Edit, and Destroy labels on the table headers
• replace the boolean completed value with a link and an icon

<h1>Here are your TODOs</h1>
...
<div class="table-responsive todos">
...
        <th>Show</th>
        <th>Edit</th>
        <th>Destroy</th>
...
        <!-- <td><%= todo.completed %></td> -->
        <td>
        <%= link_to("/todos/#{todo.id}/toggle_completed") do %>
          <% if todo.completed %>
            <span class="glyphicon glyphicon-ok"></span>
          <% else %>
            <span class="glyphicon glyphicon-unchecked"></span>
          <% end %>
         <% end %>
        </td>

6g. Edit app/views/todos/show.html.erb and add the created_at attribute:

  <dt>Created:</dt>
  <dd><%= @todo.created_at %></dd>

6h. Edit app/controllers/todos_controller.rb

• replace @todos = Todo.all with @todos = Todo.order(created_at: :desc)

• replace all occurrances of redirect_to @todo and redirect_to todos_url with redirect_to todos_path

• add a toggle_completed method:

def toggle_completed
  @todo.completed = !@todo.completed
  respond_to do |format|
    if @todo.save
      format.html { redirect_to todos_path }
      format.json { render :show, status: :ok, location: @todo }
    else
      # show some error message
    end
  end
end

• add the toggle_completed method to the before_action that is calling the set_todo method:

before_action :set_todo, only: [:show, :edit, :update, :destroy, :toggle_completed]

6i. Add a route for the toggle_completed action:

Edit config/routes.rb and add the following line:

  match 'todos/:id/toggle_completed', to: 'todos#toggle_completed', via: 'get'

6j. Commit your changes:

git add -A
git commit -m "Created MVC CRUD for a list of TODOs."
git tag step6

Intermission

Let's reflect on what we have done:

• Created a Rails app
• Added some favorite gems
• Added custom scaffolding templates
• Configured for Bootrap and SASS
• Created some static pages, a navbar, and flash message support
• Created MVC CRUD for a list of TODOs

But we have one major problem: how do we support multiple users each with their own TODO list? To do that we need to add Authentication, Authorization, and Session Management to our app. But first, lets discuss some security concepts:

Let's talk about login id, passwords and session management:

• login_id - we will use their email address
• password complexity - we will use a REGEX
• password digest - a one-way encryption so that passwords are not stored in plain text
• password confirmation - make sure the user correctly creates their password
• keep user sessions - use browser cookie containing a remember_token that is persisted in database

Step 7 - Add MVC CRUD for User

To add AuthN/AuthZ and Session Management, we first need to add a User model and its associated MVC CRUD operations to our app.

7a. Scaffold out the MVC CRUD for a User

rails g scaffold user first_name:string last_name:string email:string:uniq password_digest:string remember_token:string

7b. Edit the create_users migration script and add null: false to the first_name, last_name, email, and password_digest columns.

7c. Create a migration to add a relationship from todo to user:

rails g migration AddUserRefToTodos user:references

7d. Edit the add_user_ref_to_todos migration script and add a not-null constraint: null: false

7e. Run the migrations:

rake db:migrate

and inspect the file db/schema.rb to ensure that the model / table looks correct.

7f. Edit app/models/user.rb and add the following:

class User < ActiveRecord::Base

  has_many :todos, dependent: :destroy

  before_save { email.downcase! }

  validates :first_name, :last_name, presence: true

  VALID_EMAIL_REGEX = /\A[\w+\-.]+@[a-z\d\-]+(?:\.[a-z\d\-]+)*\.[a-z]+\z/i
  validates :email, presence: true, length: { maximum: 80 },
                    format: { with: VALID_EMAIL_REGEX },
                    uniqueness: { case_sensitive: false }

  # Add methods to set and authenticate against a BCrypt password.
  has_secure_password

  validates :password, length: { minimum: 8, maximum: 20 }

  validate :password_complexity

  def self.new_remember_token
    SecureRandom.urlsafe_base64
  end

  def self.digest(token)
    Digest::SHA1.hexdigest(token.to_s)
  end

  def password_complexity
    if password.present? and not password.match(/^(?=.*[a-z])(?=.*[A-Z])(?=.*\d)./)
      errors.add :password, "must include at least one lowercase letter, one uppercase letter, and one digit"
    end
  end

  def to_s
    email
  end
end

7g. Edit app/models/todo.rb and add the following line:

belongs_to :user

7h. Edit app/controllers/users_controller.rb and near the bottom replace the following line:

params.require(:user).permit(:first_name,
                             :last_name,
                             :email,
                             :password_digest,
                             :remember_token)

with

params.require(:user).permit(:first_name,
                             :last_name,
                             :email,
                             :password,
                             :password_confirmation)

7i. Edit app/views/users/_form.html.erb and change the password_digest and remember_token input labels and fields to:

  <div class="form-group">
    <%= f.label :password, class: "col-sm-2 control-label" %>
    <div class="col-sm-10">
      <%= f.password_field :password, class: "form-control" %>
    </div>
  </div>
  <div class="form-group">
    <%= f.label :password_confirmation, class: "col-sm-2 control-label" %>
    <div class="col-sm-10">
      <%= f.password_field :password_confirmation, class: "form-control" %>
    </div>
  </div>

7j. Edit app/views/users/edit.html.erb and remove the Back button

7k. Edit app/views/users/new.html.erb and remove the Back button and replace <h1>New user</h1> with <h1>Sign Up</h1>

7l. Edit app/views/users/show.html.erb and remove the Back button and the password_digest and remember_token fields.

7m. Commit your changes:

git add -A
git commit -m "Added MVC CRUD for User"
git tag step7

Step 8 - Create a Sessions Controller

In this step we will create a SessionsController to handle our sign-in via its new and create actions and sign-out via its destroy action. We will also modify the UsersController so that its new and create actions will handle sign-up (i.e. registration). We will also create a SessionsHelper module to provide common authentication and session management support. Finally we will add dynamically controlled navigation links so that the appropriate links appear on the navbar depending on whether the user is currently signed in.

8a. Create app/controllers/sessions_controller.rb and app/views/sessions/new.html.erb

rails g controller sessions new create destroy

8b. Edit app/views/sessions/new.html.erb and insert the following content:

<% provide(:title, "Sign in") %>
<h1>Sign in</h1>

<div class="row">
  <div class="span6 offset3">
    <%= form_for(:session, url: sessions_path) do |f| %>

      <%= f.label :email %>
      <%= f.text_field :email %>

      <%= f.label :password %>
      <%= f.password_field :password %>

      <%= f.submit "Sign in", class: "btn btn-large btn-primary" %>
    <% end %>

    <p>New user? <%= link_to "Sign up now!", signup_path %></p>
  </div>
</div>

8c. Add the following to app/helpers/sessions_helper.rb:

module SessionsHelper

  def sign_in(user)
    # save a cookie on their computer
    remember_token = User.new_remember_token
    cookies.permanent[:remember_token] = remember_token
    # update our database with their cookie info
    user.update_attribute(:remember_token, User.digest(remember_token))
    # set a current_user variable equal to user
    self.current_user = user
  end

  def signed_in?
    !current_user.nil?
  end

  # set the current_user from the remember_token cookie
  def current_user=(user)
    @current_user = user
  end

  def current_user
    remember_token  = User.digest(cookies[:remember_token])
    @current_user ||= User.find_by(remember_token: remember_token)
  end

  # check if the specified user is the current user
  def current_user?(user)
    user == current_user
  end

  # security check, ensure user is signed in, if not, redirect to signin page.
  def signed_in_user
    unless signed_in?
      store_location
      redirect_to signin_url, notice: "Please sign in."
    end
  end

  def sign_out
    current_user.update_attribute(:remember_token,
                                  User.digest(User.new_remember_token))
    cookies.delete(:remember_token)
    self.current_user = nil
  end

  # redirect back to the original requested view or to default
  def redirect_back_or(default)
    redirect_to(session[:return_to] || default)
    session.delete(:return_to)
  end

  # store the current location to support the redirect_back feature
  def store_location
    session[:return_to] = request.url if request.get?
  end
end

8d. Edit app/controllers/sessions_controller.rb to have the following content:

class SessionsController < ApplicationController

  def new
  end

  def create
    user = User.find_by(email: params[:session][:email].downcase)
    if user && user.authenticate(params[:session][:password])
      sign_in user
      redirect_back_or todos_path
    else
      flash.now[:error] = 'Invalid email/password combination'
      render 'new'
    end
  end

  def destroy
    sign_out
    redirect_to root_url
  end
end

8e. Edit app/controllers/users_controller.rb:

Modify the create method to call the sign_in helper method and change the redirect_to target path and notice:

  def create
    @user = User.new(user_params)

    respond_to do |format|
      if @user.save
        sign_in @user
        format.html { redirect_to root_path, notice: 'Welcome!' }
        format.json { render :show, status: :created, location: @user }
      else
        format.html { render :new }
        format.json { render json: @user.errors, status: :unprocessable_entity }
      end
    end
  end

8f. Edit config/routes.rb and replace

  get 'sessions/new'
  get 'sessions/create'
  get 'sessions/destroy'

with

  resources :sessions, only:[:new, :create, :destroy]

and add the following:

  match '/signup',  to: 'users#new',            via: 'get'
  match '/signin',  to: 'sessions#new',         via: 'get'
  match '/signout', to: 'sessions#destroy',     via: 'delete'

8g. Edit app/controllers/application_controller.rb and add the following line:

  include SessionsHelper

8h. Edit app/controllers/static_pages_controller.rb and add a redirect to the home action:

  def home
    redirect_to todos_path if signed_in?
  end

8i. Edit app/controllers/todos_controller.rb:

• add before_action :signed_in_user
• edit the index method:

  def index
    @todos = current_user.todos.order(created_at: :desc)
  end

• edit the create method to associate the user to a newly created Todo:

  def create
    @todo = Todo.new(todo_params)
    @todo.user = current_user       # associate the new todo to the current_user
    ...

8j. Update app/views/layouts/_navigation_links.html.erb to match the following:

<% if signed_in? %>
  <li><%= link_to 'TODOs', todos_path %></li>
  <li><%= link_to @current_user, user_path(@current_user) %></li>
  <li><%= link_to 'Sign out', signout_path, method: 'delete' %></li>
<% else %>
  <li><%= link_to 'Sign up', signup_path %></li>
  <li><%= link_to 'Sign in', signin_path %></li>
<% end %>
<li><%= link_to 'About', '/about' %></li>

8k. Edit app/views/static_pages/home.html.erb and add the following buttons to the bottom of the jumbotron:

  <br/>
  <%= link_to "Sign up now!", signup_path, class: "btn btn-large btn-primary" %>
  <%= link_to "Sign in",      signin_path, class: "btn btn-large btn-primary" %>

8l. Commit your changes:

git add -A
git commit -m "Create the Sessions Controller, Sessions Helper, and navigation links."
git tag step8

Step 9 - Add a Nice Bootswatch Theme

In this step we will add a Bootswatch theme to our project, but instead of copying the bootswatch css into our project we will use a SASSy version of Bootswatch called Bootswatch-Sass.

9a. Create the following files:

• _superhero-variables.scss - content from Superhero Variables
• _superhero.scss - content from Superhero Overrides

9b. Modify the imports in app/assets/stylesheets/application.css.scss:

@import "superhero-variables.scss";
@import "bootstrap-variables.scss";
@import "bootstrap-custom-variables.scss";
@import "bootstrap-sprockets.scss";
@import "bootstrap.scss";
@import "superhero.scss";

9c. Modify app/views/todos/index.html.erb and replace

<table class="table table-striped table-bordered table-hover">

with

<table class="table table-hover">

9d. Commit your changes:

git add -A
git commit -m "Added superhero Bootswatch theme."
git tag step9

Bonus LAB Material

• Check for security holes and fix them:
  • See what routes a user can manually enter into the browser even if the user is not logged in
  • Can a user edit the account of another user? Can a user change another user's password?
  • See if a user can manually enter the URL for a TODO that is not one of their TODOs. Can the user edit or delete TODOs that they do not own?
• Change the UX:
  • Add a nice background image.
  • Try using other Bootswatch themes.
  • Change the NavBar.
• Add some more information to a user, such as phone, city and state, occupation, etc.
• Add some more attributes to a TODO, such as a due_date and a priority.
• Add a set of keywords to a Todo. There should be a many-to-many relationship between todos and keywords and the code should not create duplicate keywords.
• Replace the manual authentication with a gem like Devise.

Step 10 - Patch Security Holes

10a. Edit app/controllers/users_controller.rb and do the following:

• Add the following before actions:

   before_action :signed_in_user, only: [:index, :show, :edit, :update, :destroy]
   before_action :verify_correct_user, only: [:show, :edit, :update, :destroy]

• Add the verify_correct_user private method:

     def verify_correct_user
       user = User.find_by(id: params[:id])
       redirect_to root_url, notice: 'Access Denied!' unless current_user?(user)
     end

10b. Edit app/controllers/todos_controller.rb and do the following:

• Add the following before actions:

  before_action :signed_in_user
  before_action :set_todo, only: [:toggle_completed, :show, :edit, :update, :destroy]
  before_action :verify_correct_user, only: [:show, :edit, :update, :destroy]

• Add the verify_correct_user private method:

     def verify_correct_user
       @todo = current_user.todos.find_by(id: params[:id])
       redirect_to root_url, notice: 'Access Denied!' if @todo.nil?
     end

Step 11 - Deploy to Heroku

11a. Make sure you have a Heroku account - https://signup.heroku.com/login

11b. Download and install the Heroku Toolbelt - https://toolbelt.heroku.com/

11c. Add the rails_12factor gem to the Gemfile:

gem 'rails_12factor', group: :production

Then run bundle install and save your work:

bundle install
git add -A
git commit -m "Added rails_12factor"
git tag step11

11d. Configure your git repo for Heroku, push to Heroku, and run a db:migrate remotely on Heroku:

heroku create
git push heroku master
heroku run rake db:migrate
heroku open

Helpful Heroku Commands

Managing Your App

heroku open                                 # open your app in a browser tab
heroku ps                                   # see the status of your heroku servers
heroku logs                                 # view the logs
heroku addons:create heroku-postgresql:dev  # add a PostgreSQL development DB
heroku addons:create mongolab:sandbox       # add a MongoLab DB
heroku run rake db:migrate                  # run db migrations
heroku run rake db:seed                     # run seeds.rb file
heroku run:detached rake db:migrate         # run detached from Terminal

Debugging

heroku ps             # list process status of heroku processes
heroku releases       # list releases deployed to heroku for current app
heroku logs           # display logs for an app
heroku logs -n 1500   # default is 100 lines, but you can get up to 1500
heroku login          # authenticate with heroku so that you can connect
heroku run bash       # connect to heroku host machine

General Commands

heroku help                             # prints help
heroku list                             # list all of your heroku apps
heroku info                             # prints info about the heroku project
heroku config                           # prints heroku environment variables
heroku config:set NODE_ENV=development  # set environment variable
heroku apps:rename <new_name>           # rename a heroku project; changes URL