Switch to GitHub Actions

* Use GitHub Actions for CI
* Update Coveralls integration: generate lcov report with SimpleCov and
  send it after the test suite using coveralls GitHub Actions plugin
* Update and cleanup RSpec config
* Cleanup Rakefile
* Remove active_model dependency (certificate_authority was fixed)

PS: GH Actions syntax is ugly.
  Should we switch to Cirlce CI or GitLab CI? XD

Resolves: #633

.github/workflows/ci.yml

@@ -0,0 +1,80 @@
+name: CI
+
+on:
+  push:
+    branches: [ master ]
+  pull_request:
+    branches: [ master ]
+
+jobs:
+  test:
+    runs-on: ${{ matrix.os }}
+
+    strategy:
+      matrix:
+        ruby: [ ruby-2.4, ruby-2.5, ruby-2.6, ruby-2.7, jruby-9.2.11 ]
+        os: [ ubuntu-latest, macos-latest, windows-latest ]
+
+    steps:
+      - uses: actions/checkout@v2
+
+      - uses: ruby/setup-ruby@v1
+        with:
+          ruby-version: ${{ matrix.ruby }}
+
+      - uses: actions/cache@v1
+        with:
+          path: vendor/bundle
+          key: bundle-use-ruby-${{ matrix.os }}-${{ matrix.ruby }}-${{ hashFiles('**/Gemfile.lock') }}
+          restore-keys: bundle-use-ruby-${{ matrix.os }}-${{ matrix.ruby }}-
+
+      - name: bundle install
+        run: |
+          bundle config set path "vendor/bundle"
+          bundle config set without "development"
+          bundle install --jobs 4
+
+      - run: bundle exec rspec --format progress --force-colour
+
+      - name: Prepare Coveralls test coverage report
+        uses: coverallsapp/[email protected]
+        with:
+          github-token: ${{ secrets.GITHUB_TOKEN }}
+          flag-name: "${{ matrix.ruby }} @${{ matrix.os }}"
+          path-to-lcov: ./coverage/lcov/lcov.info
+          parallel: true
+
+  coveralls:
+    needs: test
+    runs-on: ubuntu-latest
+    steps:
+      - name: Finalize Coveralls test coverage report
+        uses: coverallsapp/github-action@master
+        with:
+          github-token: ${{ secrets.GITHUB_TOKEN }}
+          parallel-finished: true
+
+  lint:
+    runs-on: ubuntu-latest
+
+    steps:
+      - uses: actions/checkout@v2
+
+      - uses: ruby/setup-ruby@v1
+        with:
+          ruby-version: 2.4
+
+      - uses: actions/cache@v1
+        with:
+          path: vendor/bundle
+          key: bundle-use-ruby-lint-${{ hashFiles('**/Gemfile.lock') }}
+          restore-keys: bundle-use-ruby-lint-
+
+      - name: bundle install
+        run: |
+          bundle config set path "vendor/bundle"
+          bundle config set without "development"
+          bundle install --jobs 4
+
+      - run: bundle exec rubocop --color
+      - run: bundle exec rake verify_measurements

.gitignore

@@ -1,19 +1,15 @@
 *.gem
-.bundle
 .config
 .rvmrc
-.ruby-version
 .yardoc
-Gemfile.lock
 InstalledFiles
 _yardoc
-coverage
+
+.bundle
+.ruby-version
 doc
-lib/bundler/man
-measurement
+coverage
 pkg
-rdoc
-spec/reports
-test/tmp
-test/version_tmp
+spec/examples.txt
 tmp
+Gemfile.lock

.rspec

@@ -1,5 +1 @@
---backtrace
---color
---format=documentation
---order random
 --require spec_helper

Gemfile

@@ -10,20 +10,21 @@ group :development do
   gem "nokogiri",    :require => false
   gem "pry",         :require => false
 
-  platform :ruby_20 do
-    gem "pry-debugger",       :require => false
-    gem "pry-stack_explorer", :require => false
+  # RSpec formatter
+  gem "fuubar", :require => false
+
+  platform :mri do
+    gem "pry-byebug"
   end
 end
 
 group :test do
-  gem "activemodel", :require => false # Used by certificate_authority
   gem "certificate_authority", :require => false
 
   gem "backports"
 
-  gem "coveralls", :require => false
-  gem "simplecov", ">= 0.9"
+  gem "simplecov",      :require => false
+  gem "simplecov-lcov", :require => false
 
   gem "rspec", "~> 3.0"
   gem "rspec-its"

Rakefile

@@ -61,12 +61,4 @@ task :generate_status_codes do
   end
 end
 
-if ENV["CI"].nil?
-  task :default => %i[spec rubocop verify_measurements]
-else
-  case ENV["SUITE"]
-  when "rubocop"   then task :default => :rubocop
-  when "yardstick" then task :default => :verify_measurements
-  else                  task :default => :spec
-  end
-end
+task :default => %i[spec rubocop verify_measurements]

spec/spec_helper.rb

@@ -1,19 +1,7 @@
 # frozen_string_literal: true
 
-require "simplecov"
-require "coveralls"
-
-SimpleCov.formatter = SimpleCov::Formatter::MultiFormatter.new(
-  [
-    SimpleCov::Formatter::HTMLFormatter,
-    Coveralls::SimpleCov::Formatter
-  ]
-)
-
-SimpleCov.start do
-  add_filter "/spec/"
-  minimum_coverage 80
-end
+require_relative "./support/simplecov"
+require_relative "./support/fuubar" unless ENV["CI"]
 
 require "http"
 require "rspec/its"
@@ -40,6 +28,13 @@
     mocks.verify_partial_doubles = true
   end
 
+  # This option will default to `:apply_to_host_groups` in RSpec 4 (and will
+  # have no way to turn it off -- the option exists only for backwards
+  # compatibility in RSpec 3). It causes shared context metadata to be
+  # inherited by the metadata hash of host groups and examples, rather than
+  # triggering implicit auto-inclusion in groups with matching metadata.
+  config.shared_context_metadata_behavior = :apply_to_host_groups
+
   # These two settings work together to allow you to limit a spec run
   # to individual examples or groups you care about by tagging them with
   # `:focus` metadata. When nothing is tagged with `:focus`, all examples
@@ -48,17 +43,22 @@
   config.filter_run_excluding :flaky if defined?(JRUBY_VERSION) && ENV["CI"]
   config.run_all_when_everything_filtered = true
 
-  # Limits the available syntax to the non-monkey patched syntax that is recommended.
-  # For more details, see:
-  #   - http://myronmars.to/n/dev-blog/2012/06/rspecs-new-expectation-syntax
-  #   - http://teaisaweso.me/blog/2013/05/27/rspecs-new-message-expectation-syntax/
-  #   - http://myronmars.to/n/dev-blog/2014/05/notable-changes-in-rspec-3#new__config_option_to_disable_rspeccore_monkey_patching
-  config.disable_monkey_patching!
-
   # This setting enables warnings. It's recommended, but in some cases may
   # be too noisy due to issues in dependencies.
   config.warnings = 0 == ENV["GUARD_RSPEC"].to_i
 
+  # Allows RSpec to persist some state between runs in order to support
+  # the `--only-failures` and `--next-failure` CLI options. We recommend
+  # you configure your source control system to ignore this file.
+  config.example_status_persistence_file_path = "spec/examples.txt"
+
+  # Limits the available syntax to the non-monkey patched syntax that is
+  # recommended. For more details, see:
+  #   - http://rspec.info/blog/2012/06/rspecs-new-expectation-syntax/
+  #   - http://www.teaisaweso.me/blog/2013/05/27/rspecs-new-message-expectation-syntax/
+  #   - http://rspec.info/blog/2014/05/notable-changes-in-rspec-3/#zero-monkey-patching-mode
+  config.disable_monkey_patching!
+
   # Many RSpec users commonly either run the entire suite or an individual
   # file, and it's useful to allow more verbose output when running an
   # individual spec file.

spec/support/fuubar.rb

@@ -0,0 +1,21 @@
+# frozen_string_literal: true
+
+require "fuubar"
+
+RSpec.configure do |config|
+  # Use Fuubar instafail-alike formatter, unless a formatter has already been
+  # configured (e.g. via a command-line flag).
+  config.default_formatter = "Fuubar"
+
+  # Disable auto-refresh of the fuubar progress bar to avoid surprises during
+  # debugiing. And simply because there's next to absolutely no point in having
+  # this turned on.
+  #
+  # > By default fuubar will automatically refresh the bar (and therefore
+  # > the ETA) every second. Unfortunately this doesn't play well with things
+  # > like debuggers. When you're debugging, having a bar show up every second
+  # > is undesireable.
+  #
+  # See: https://github.com/thekompanee/fuubar#disabling-auto-refresh
+  config.fuubar_auto_refresh = false
+end

spec/support/simplecov.rb

@@ -0,0 +1,19 @@
+# frozen_string_literal: true
+
+require "simplecov"
+
+if ENV["CI"]
+  require "simplecov-lcov"
+
+  SimpleCov::Formatter::LcovFormatter.config do |config|
+    config.report_with_single_file = true
+    config.lcov_file_name          = "lcov.info"
+  end
+
+  SimpleCov.formatter = SimpleCov::Formatter::LcovFormatter
+end
+
+SimpleCov.start do
+  add_filter "/spec/"
+  minimum_coverage 80
+end