BetaMax + JUnit + Gradle works

This is just a quick demo of BetaMax, Junit, and Gradle, working together. RetroFit is also used.

It was easy to set up, my only problem was that I had to include groovy explicitly, and that version it had to be version 2.2.0 (rather than 2.3.3), due to a bug.

Run the tests

./gradlew build