Low level GeoJson implementation

Nobody has claimed this yet.

This is a request for either a rewrite or alternative implementation of the current GeoJson module found [here](https://github.com/mapbox/mapbox-java/blob/master/services-geojson). We need a high performance implementation that has a minimal memory footprint. The reasoning behind that is that geojson models should be scalable (eg. downstream we query the map for 1000 of features, the path currently taken to create those and the intermediate objects created for doing that isn't optimal atm).

Couple of thoughts to improve this:
- use primitive instead of objects where possible
- no need for AutoValue, implementation is based on a specification that doesn't change (often)
- if geojson models are immutable, use arrays instead of List
- limit method invocations & don't allocate memory if you can avoid it
- don't over abstract concepts if they can be expressed more simple

More information on performance tips [here](https://developer.android.com/training/articles/perf-tips.html)
RFC of GeoJSON can be found [here](https://tools.ietf.org/html/rfc7946).

cc @mapbox/android

Start by reviewing the current implementation in services-geojson, then compare its model structure with RFC 7946 and the linked Android performance tips. Define how the rewrite or alternative will measure memory footprint and performance for roughly 1,000 features; done means the GeoJSON models meet the requested scalability goals without unnecessary allocations or abstractions.

Written by the indexing model from the issue text.