Register for local notifications in iOS 8

> In iOS 8 and later, apps that use either local or remote notifications must register the types of notifications they intend to deliver.

See: https://developer.apple.com/library/iOs/documentation/NetworkingInternet/Conceptual/RemoteNotificationsPG/Chapters/IPhoneOSClientImp.html#//apple_ref/doc/uid/TP40008194-CH103-SW1