Common http stack

[tobrun]

This issue captures reusing a Http interface for our native libraries across Android projects. The project setup in this repository must follow modular requirements so end users can swap out the default implementation with their own.

• add new android library project
• include bintray published binary with native implementation (so file)
• implement HttpServiceInterface using OkHttp 4.x
• release to Bintray

cc @mapbox/maps-android

[tobrun]

We will be solely hosting the interface for the http stack in this repo

[zugaldia]

Has the interface for this HTTP stack been committed to this repo already, or is it still pending?

[tobrun]

yes #19