Pull private key into separate file
Update to Google Maps SDK for iOS version: 1.3.0.3430

- Updated GMS framework
- Updated lib++ framework
- Changes to GMSMarker code as required to match in with SDK changes
(see https://developers.google.com/maps/documentation/ios/releases)
Reorganize frameworks in xcode project
Refactor draggable marker code into separate helper class

- Adds GMDraggableMarkerManager
- Adds GMDraggableMarkerManagerDelegate
- View controller now implements GMDraggableMarkerManagerDelegate to
receive drag events
- All dragging related code moved out of view controller