Merge both frameworks into a single podspec

[1ec5]

MapboxCoreNavigation is now a subspec of MapboxNavigation.

Fixes #108.

/cc @frederoni @bsudekum

[1ec5]

This isn’t working correctly yet. If you use pod 'MapboxNavigation', CocoaPods winds up creating a MapboxNavigation.framework target but not a MapboxCoreNavigation.framework target. As a result, any import MapboxCoreNavigation statement in MapboxNavigation causes a build failure:

/path/to/mapbox-navigation-ios/MapboxNavigation/MGLMapView.swift:4:8: No such module 'MapboxCoreNavigation'

[1ec5]

If you use pod 'MapboxNavigation/MapboxCoreNavigation', CocoaPods creates a MapboxNavigation.framework target, which means you have to import MapboxNavigation rather than MapboxCoreNavigation.

[1ec5]

We may have to create a custom modulemap for the outer MapboxNavigation pod and specify it in the podspec using the module_map directive. But I’m not sure whether the subspec will be able to override the outer pod’s module_map directive to include its own classes.

[1ec5]

I don’t see a good way forward on this issue: using a subspec for Mapbox Core Navigation is tantamount to merging it and Mapbox Navigation into the same product, which we need to avoid.