Mapbox Java SDK v5.0.0-beta.1

README update for 5.0.0 release

Changelog updates for stable 4.9.0 release (mapbox#1080)

changelog updates for 4.9.0-alpha.1 release

Release 4.8.0 (mapbox#1030)

Release 4.8.0-alpha.3 (mapbox#1029)

updated changelog for 4.8.0-apha.2 release (mapbox#1026)

Changelog for 4.8.0-alpha.1 release (mapbox#1023)

Changelog for 4.8.0-alpha.1 release (mapbox#1023)

Added @keep annotation to ease integration of geojson library (mapbox…

…#1005)