* Add roundaboutExits param to MapboxDirections

Added roundaboutExits param to MapboxDirections.

Still need to add fixtures, test and check param description

* address PR review comments

* add test fixture

* add test

* fix fixture generation

* remove unused import

* add constants to reflect two new types

* fix line length

* omit originalRequestIdentifier, requestIdentifier and audioType optional fields over sending nulls

* add support for null json literals

* added missing events

* added starttime

* Add sdkIdentifier + sdkversion

- add parameters to initialization call
- add fields to MapboxEvent
- set sdkIdentifier and sdkVersion when pushing turnstile event
- write fallback method to preserve backwards compatability with previous versions

* fix version name to release 2.2.5

* change version name back to 2.3.0-SNAPSHOT

* updated changelog for 2.2.4 and 2.2.5

* [WIP] make location provider optional

* [WIP] fix location engine provider providing only those that are available

* fix location engine provider public api and remove classes not necessary anymore

* fix location engine provider public APIs

* bump dependencies (build tools, support libraries, mapbox and lost) and address PR comments

* ignore location engine coming from mapbox-android-sdk momentarily so that CI passes (chicken-egg problem)

* fix naming

* fix some breaking API changes

* fix obtain best location engine not returning default location engine in some cases

…cation engine was already connected (mapbox#587)

- allow system to handle null variables and pass along null json objects when they are found

- make sure getStepMetadata is return json object for the step field within event

… builder (mapbox#588)

…x#593)

* make lost dependency provided

* reverted back to lost 1.1

* reverted lost to 1.1

* restored circle script to build from master

* removed deprecated tag

* [android] [auto] Update properties to version 2.2.6 in preparation for build.

* temporarily edit circle script for release

* revert 2.2.6 changes

* updated changelog

- add in a null check for batteryStatus
- takes care of bug associated with phones that don't report battery status

- change flushEventsQueueImmediately to public

- switch volume return from system volume to the music volume