Add beta testing guide

BETA_TESTING.md

@@ -0,0 +1,25 @@
+# Beta Testing OneBusAway Android
+
+We provide early access to new versions of OneBusAway Android via Google Play's [beta testing](https://developer.android.com/distribute/googleplay/developer-console.html#alpha-beta) platform.  This helps us get feedback on bug fixes and new features before they are distributed to all users.
+
+Please note that these versions are not as heavily tested as production releases and, as a result, may not be as stable.
+
+## Register as a beta tester
+
+1. Join the [onebusaway-developers Google Group](https://groups.google.com/forum/#!forum/onebusaway-developers) using a Google account
+2. Go to https://play.google.com/apps/testing/com.joulespersecond.seattlebusbot and opt in for testing (using the same Google account)
+3. Download the app from [Google Play](https://play.google.com/store/apps/details?id=com.joulespersecond.seattlebusbot) (using the same Google account) - you'll now have access to the beta version!
+
+You only have to complete the above steps once.  Unless you opt-out (using the same link in #2 above), you'll continue to receive new beta versions as they are released.
+
+Please note that you need to use the same Google account for all three steps above, or you won't get access to the beta.
+
+## How to provide feedback
+
+Please let us know if you experience problems with a beta, or would like to give general feedback (good and bad)!
+
+You can reach us via:
+
+* Email - android-app (at) onebusaway.org
+* Posting a messsage on the [onebusaway-developers Google Group](https://groups.google.com/forum/#!forum/onebusaway-developers)
+* Filing a issue on the [OBA Android Github issue tracker](https://github.com/OneBusAway/onebusaway-android/blob/master/CONTRIBUTING.md#issue-tracker)

README.md

@@ -51,6 +51,10 @@ key.alias=<key_alias_name>
 
 Note that the paths in these files always use the Unix path separator `/`, even on Windows. If you use the Windows path separator `\` you will get the error `No value has been specified for property 'signingConfig.keyAlias'.`
 
+### Beta testing
+
+Get early access to new OneBusAway Android versions!  See our [Beta Testing Guide](https://github.com/OneBusAway/onebusaway-android/blob/master/BETA_TESTING.md) for details.
+
 ### Contributing
 
 We welcome contributions to the project! Please see our [Contributing Guide](https://github.com/OneBusAway/onebusaway-android/blob/master/CONTRIBUTING.md) for details, including Code Style Guidelines and Template.