Currently the layer cannot be selected for low zoom levels.

It would be useful if a missing property in the config file fell back gracefully to the default value, rather than killing the process with a hard error.

Is there any appetite for such a change? We could potentially specify default values in a json file that the C++ code reads at compile time and the python script valhalla_build_config parses at runtime?

NavigationMapView should automatically switch to the night style when the Smart Invert Colors option is enabled in iOS 11, based on UIAccessibilityIsInvertColorsEnabled() or the [UIAccessibilityInvertColorsStatusDidChange](https://developer.apple.com/documentation/foundation/nsnotification.name/1615196-

This is a feature request, not a bug.
Although this module is awesome, integration with Bolt would make it even more so :)

If a developer attempts to calculate directions with more than three waypoints, the following error is returned:

Error Domain=MBDirectionsErrorDomain Code=-1 "Too many coordinates;
maximum number of coordinates is 3." 
UserInfo={NSLocalizedFailureReason=Too many coordinates;
maximum number of coordinates is 3.}

It appears the [Mapbox Directions API](https://www.mapbox.com/api-d