Reactive Architecture demo

[David González]

It'd be great to have a demo showcasing how we deal with a reactive architecture. The example could parse a json and display some information in a fragment.

The goal is to show how to deal with networking calls and data treatment using a reactive approach.

[Friedger]

A tiny rx demo is at https://github.com/novoda/rxpresso/tree/master/demo

[Paul Blundell]

this will appear in a new repo