Merge PR #1422: Add Contributing Guidelines

* Merge pull request #1422: Add Contributing Guidelines
* cwgoes comments

CHANGELOG.md

@@ -79,6 +79,7 @@ IMPROVEMENTS
 * [stake] edit-validator changes now can use the keyword [do-not-modify] to not modify unspecified `--flag` (aka won't set them to `""` value)
 * [types] added common tag constants
 * [stake] offload more generic functionality from the handler into the keeper
+* added contributing guidelines
 
 ## 0.19.0
 

CONTRIBUTING.md

@@ -0,0 +1,105 @@
+# Contributing
+
+Thank you for considering making contributions to Cosmos-SDK and related repositories! Start by taking a look at this [coding repo](https://github.com/tendermint/coding) for overall information on repository workflow and standards.
+
+Please follow standard github best practices: fork the repo, branch from the tip of develop, make some commits, and submit a pull request to develop. See the [open issues](https://github.com/cosmos/cosmos-sdk/issues) for things we need help with!
+
+Please make sure to use `gofmt` before every commit - the easiest way to do this is have your editor run it for you upon saving a file. Additionally please ensure that your code is lint compliant by running `make lint`
+
+Looking for a good place to start contributing? How about checking out some [good first issues](https://github.com/cosmos/cosmos-sdk/issues?q=is%3Aopen+is%3Aissue+label%3A%22good+first+issue%22)
+
+## Forking
+
+Please note that Go requires code to live under absolute paths, which complicates forking.
+While my fork lives at `https://github.com/rigeyrigerige/cosmos-sdk`,
+the code should never exist at  `$GOPATH/src/github.com/rigeyrigerige/cosmos-sdk`.
+Instead, we use `git remote` to add the fork as a new remote for the original repo,
+`$GOPATH/src/github.com/cosmos/cosmos-sdk `, and do all the work there.
+
+For instance, to create a fork and work on a branch of it, I would:
+
+  * Create the fork on github, using the fork button.
+  * Go to the original repo checked out locally (i.e. `$GOPATH/src/github.com/cosmos/cosmos-sdk`)
+  * `git remote rename origin upstream`
+  * `git remote add origin [email protected]:ebuchman/basecoin.git`
+
+Now `origin` refers to my fork and `upstream` refers to the Cosmos-SDK version.
+So I can `git push -u origin master` to update my fork, and make pull requests to Cosmos-SDK from there.
+Of course, replace `ebuchman` with your git handle.
+
+To pull in updates from the origin repo, run
+
+    * `git fetch upstream`
+    * `git rebase upstream/master` (or whatever branch you want)
+
+Please don't make Pull Requests to `master`.
+
+## Dependencies
+
+We use [dep](https://github.com/golang/dep) to manage dependencies.
+
+That said, the master branch of every Cosmos repository should just build
+with `go get`, which means they should be kept up-to-date with their
+dependencies so we can get away with telling people they can just `go get` our
+software.
+
+Since some dependencies are not under our control, a third party may break our
+build, in which case we can fall back on `dep ensure` (or `make
+get_vendor_deps`). Even for dependencies under our control, dep helps us to
+keep multiple repos in sync as they evolve. Anything with an executable, such
+as apps, tools, and the core, should use dep.
+
+Run `dep status` to get a list of vendor dependencies that may not be
+up-to-date.
+
+## Testing
+
+All repos should be hooked up to [CircleCI](https://circleci.com/).
+
+If they have `.go` files in the root directory, they will be automatically
+tested by circle using `go test -v -race ./...`. If not, they will need a
+`circle.yml`. Ideally, every repo has a `Makefile` that defines `make test` and
+includes its continuous integration status using a badge in the `README.md`.
+
+## Branching Model and Release
+
+User-facing repos should adhere to the branching model: http://nvie.com/posts/a-successful-git-branching-model/.
+That is, these repos should be well versioned, and any merge to master requires a version bump and tagged release.
+
+Libraries need not follow the model strictly, but would be wise to.
+
+The SDK utilizes [semantic versioning](https://semver.org/).
+
+### Development Procedure:
+- the latest state of development is on `develop`
+- `develop` must never fail `make test` or `make test_cli`
+- `develop` should not fail `make test_lint`
+- no --force onto `develop` (except when reverting a broken commit, which should seldom happen)
+- create a development branch either on github.com/cosmos/cosmos-sdk, or your fork (using `git remote add origin`)
+- before submitting a pull request, begin `git rebase` on top of `develop`
+
+### Pull Merge Procedure:
+- ensure pull branch is rebased on develop
+- run `make test` and `make test_cli` to ensure that all tests pass
+- merge pull request
+- push master may request that pull requests be rebased on top of `unstable`
+
+### Release Procedure:
+- start on `develop`
+- prepare changelog/release issue
+- bump versions
+- push to release-vX.X.X to run CI
+- merge to master
+- merge master back to develop
+
+### Hotfix Procedure:
+- start on `master`
+- checkout a new branch named hotfix-vX.X.X
+- make the required changes
+  - these changes should be small and an absolute necessity
+  - add a note to CHANGELOG.md
+- bump versions
+- push to hotfix-vX.X.X to run the extended integration tests on the CI
+- merge hotfix-vX.X.X to master
+- merge hotfix-vX.X.X to develop
+- delete the hotfix-vX.X.X branch