Moves build script dependencies in root build.gradle
Makes robolectric-tests an Android module. Fixes Robolectric config accordingly.
Enables jacoco reports for robolectric tests
Enables jacoco for core module too.
Applies `com.android.library` plugin in `/robolectric-tests` module to avoid problems with build task.
Updates README to include JaCoCo support
Merge pull request #2 from mr-archano/master

Robolectric and JaCoCo setup