Adding apns to backend

Use it this way:
APNS.send_notification(device_token, message_string)
Remove debugger line
Skeleton test
Merge branch 'master' into backend_push_notification

Conflicts:
	backend/Gemfile
	backend/Gemfile.lock
Merge branch 'backend_push_notification' into post-locations
Skeletal implementation of post bookings
Skeletal implementation of post bookings