directions

Currently the layer cannot be selected for low zoom levels.

Would be nice to tell a user when certain things happen while processing, e.g. clamping values to their allowed maximum, enabling destination_only roads in 2. pass, deprecating request parameters etc.

IMO it should be a top-level warnings array of strings which is empty by default and all modules can add their share during processing: probably implement the most obvious ones first and add o

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-

At the https://github.com/flexible-agency/react-native-map-link/blob/master/src/index.js#L42

we verify if params are in the options, but do not check the value, so for undefined we have

parseFloat(undefined); // NaN

for sure it can be fixed in the client code, but seems like nice to handle it inside the lib

![image](https://user-images.githubusercontent.com/6904368/11311

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