Push notification deos not work in swift 3.0 :  intial we import the import UserNotifications framework 
and we intialize the delegate mehtod in appdelegate.swift class

 if #available(iOS 10.0, *){
            
            UNUserNotificationCenter.current().delegate = self
            let center = UNUserNotificationCenter.current()
            center.requestAuthorization(options:[.badge, .alert, .sound]) { (granted, error) in
                if (granted)
                {
                    UIApplication.shared.registerForRemoteNotifications()
                }
                else{
                    //Do stuff if unsuccessful...
                }
                // Enable or disable features based on authorization.
            }
            
        }
