chore: add Pojos (along with the ability to test them independently)

drive for this: https://groups.google.com/forum/#!topic/adt-dev/q62wePcjK7o
useful guides:

* http://stackoverflow.com/questions/17536652/gradle-and-multi-project-structure
* https://github.com/ethankhall/AndroidComplexBuild
docs: updated README with features