Implemement push notifications handling with new API #39
Description
[UIApplicationDelegate didReceiveRemoteNotification] is deprecated, need to move to the new "UN" API:
Use UserNotifications Framework's -[UNUserNotificationCenterDelegate willPresentNotification:withCompletionHandler:] or -[UNUserNotificationCenterDelegate didReceiveNotificationResponse:withCompletionHandler:] for user visible notifications and -[UIApplicationDelegate application:didReceiveRemoteNotification:fetchCompletionHandler:] for silent remote notifications