Sample Project

This PR is for discussion only do not merge :x: 

Here is the sample application showcasing usage of all features present in the previous PRs.
This is because of the hack module from the RxAndroid base project.
Since the dependencies on the nebula plugins are conflicting with android plugins, in order to create android demo samples, the android module is not a gradle module directly linked, it has a separate gradle wrapper and this gradle is called by a script at the right time in the parent project lifecycle. This line then pulls down the properties from the parent project to avoid config duplications.

It is a really hackish solution which will hopefully be resolved since nebula plugins are changing.