added jacoco and coveralls integration
Change Gradle plugin ids to be Gradle Plugin Portal compatible (i.e. qualified)

Closes #394.
modified coveralls properties to support multi module jacoco report
Merge pull request #402 from kramer/master

Add Jacoco & Coveralls integration 

Closes #398.
Some cleanup and fixes for code coverage.

#398
Make Jacoco report task depend on test tasks.

#398
Remove unused class.
Add coverage badge.
Add some more coveralls integration.