add CONTRIBUTING guide

CONTRIBUTING.md

@@ -0,0 +1,22 @@
+# Contributing
+
+## Submitting an Issue
+We use the [GitHub issue tracker](https://github.com/cloudfoundry/bosh-gcscli/issues) to track bugs and features.
+Before submitting a bug report or feature request, check to make sure it hasn't already been submitted. You can indicate
+support for an existing issue by voting it up. When submitting a bug report, please include a
+[Gist](http://gist.github.com/) that includes a stack trace and any details that may be necessary to reproduce the bug,
+including your gem version, Ruby version, and operating system. Ideally, a bug report should include a pull request with failing specs.
+
+## Submitting a Pull Request
+You can add a feature or bug-fix via pull request.
+1. Fork the project
+1. Create a branch for your feature or fix from the `develop` branch. Replace `your-feature-name` with a description of your feature or fix:
+   ```
+   git checkout -b your-feature-name develop
+   ```
+1. Implement your feature or bug fix
+1. Commit and push your changes
+1. Submit a pull request to the `develop` branch of the [bosh-gcscli] repository. PRs to the master branch are not accepted.
+1. Unit tests and a BOSH release are created for each PR. You should see the status of your PR change to "pending" within a few minutes of submitting it, and then to "passed" or "failed" within 10 minutes.
+
+[bosh-gcscli]: https://github.com/cloudfoundry/bosh-gcscli/

README.md

@@ -76,6 +76,10 @@ The command line tool expects a JSON configuration file. Run `bosh-gcscli --help
 * A Makefile is provided that automates integration testing. Try `make help` to get started.
 * [gvt](https://godoc.org/github.com/FiloSottile/gvt) is used for vendoring.
 
+## Contributing
+
+For details on how to contribute to this project - including filing bug reports and contributing code changes - please see [CONTRIBUTING.md](./CONTRIBUTING.md).
+
 ## License
 
 This tool is licensed under Apache 2.0. Full license text is available in [LICENSE](LICENSE).