Adds CONTRIBUTING guidelines doc

[finishes #150696818]

Signed-off-by: Joe Kirwin <jkirwin@pivotal.io>

Author: Anoop Gopalakrishnan

CONTRIBUTING.md

@@ -0,0 +1,61 @@
+# Contributing to BOSH-Process-Manager (BPM)
+
+The BPM team uses GitHub and accepts contributions via [pull request](https://help.github.com/articles/using-pull-requests).
+
+The `bpm-release` repository is a [BOSH](https://github.com/cloudfoundry/bosh) release for BPM. The root of this repository doubles as a Golang [`GOPATH`](https://golang.org/doc/code.html#GOPATH).
+For more information about configuring your Golang environment and automatically setting your `GOPATH` to the release directory.
+
+Changes are via pull request (PR) to the master branch of its repository. 
+
+Please verify your changes before submitting the PR by following the [Testing](#testing) section below.
+
+---
+
+## Contributor License Agreement
+
+Follow these steps to make a contribution to any of our open source repositories:
+
+1. Ensure that you have completed our CLA Agreement for [individuals](https://www.cloudfoundry.org/wp-content/uploads/2015/07/CFF_Individual_CLA.pdf) or [corporations](https://www.cloudfoundry.org/wp-content/uploads/2015/07/CFF_Corporate_CLA.pdf).
+
+2. Set your name and email (these should match the information on your submitted CLA)
+  ```
+  git config --global user.name "Firstname Lastname"
+  git config --global user.email "your_email@example.com"
+  ```
+
+3. All contributions must be sent using GitHub pull requests as they create a nice audit trail and structured approach.
+
+The originating github user has to either have a github id on-file with the list of approved users that have signed
+the CLA or they can be a public "member" of a GitHub organization for a group that has signed the corporate CLA.
+This enables the corporations to manage their users themselves instead of having to tell us when someone joins/leaves an organization. By removing a user from an organization's GitHub account, their new contributions are no longer approved because they are no longer covered under a CLA.
+
+If a contribution is deemed to be covered by an existing CLA, then it is analyzed for engineering quality and product
+fit before merging it.
+
+If a contribution is not covered by the CLA, then the automated CLA system notifies the submitter politely that we
+cannot identify their CLA and ask them to sign either an individual or corporate CLA. This happens automatically as a
+comment on pull requests.
+
+When the project receives a new CLA, it is recorded in the project records, the CLA is added to the database for the
+automated system uses, then we manually make the Pull Request as having a CLA on-file.
+
+----
+
+## Testing
+
+### Prerequisites:
+  - [Install Docker](https://docs.docker.com/engine/installation/)
+
+1. To run the unit test suite in a docker image
+```bash
+$ cd bpm-release
+$ ./script/test-with-docker
+```
+
+2. To run the acceptance tests against docker
+```bash
+$ cd bpm-release
+$ ./scripts/start-docker # this will launch you into the docker shell
+/go# /bpm/scripts/start-test-agent
+/go# ginkgo -r -p -race /bpm/src/bpm-acceptance/ -- --agent-uri="http://127.0.0.1:1337"
+```