title: UNUserNotificationCenter didRecieve Response is not called if App is terminated
body: <p>UNUserNotificationCenter function is not called on clicking <strong>Action Button</strong> Chat in Notification after 3D Touch if App is not active(not even in Background or say has terminated). I used "attach to process by name" in Xcode to debug app when app was terminated. Here is the Code:</p>
  
  <pre><code>import UIKit
  import Mixpanel
  import UserNotifications
  
  @UIApplicationMain
  
  class AppDelegate: UIResponder, UIApplicationDelegate, UNUserNotificationCenterDelegate {
  
      func application(_ application: UIApplication, didFinishLaunchingWithOptions launchOptions: [NSObject: AnyObject]?) -&gt; Bool {
          //setup mixpanel
  
          self.handlePushNotificationWithUserInfo(launchOptions: launchOptions)
  
          //ask for push notification perms
          return true
      }
  </code></pre>
  
  <p>When Notification Pop-up (Sent from MixPanel) this function is called first,</p>
  
  <p>Call 1:</p>
  
  <pre><code>    func handlePushNotificationWithUserInfo(launchOptions: [NSObject: AnyObject]?) {
          //Handle PushNotification when app is opened
      }
  </code></pre>
  
  <p>Then It goes here,</p>
  
  <p>Call 2:</p>
  
  <pre><code>    //register for notification
      func application(_ application: UIApplication, didRegister notificationSettings: UIUserNotificationSettings) {
  
          if #available(iOS 10.0, *) {
              let center = UNUserNotificationCenter.current()
              center.requestAuthorization(options: [.alert, .sound]) { (granted, error) in
                  // Enable or disable features based on authorization.
              }
              center.delegate = self
  
              let actionChat = UNNotificationAction(identifier: Constants.ActionType.CHAT.rawValue, title: "Chat", options: [.foreground])
              let categoryOptions = UNNotificationCategoryOptions(rawValue: 0)
              let customerSupportCategory = UNNotificationCategory(identifier: Constants.NotificationType.CUSTOMER_SUPPORT.rawValue, actions: [actionChat], intentIdentifiers: [], options: categoryOptions)
              center.setNotificationCategories([customerSupportCategory])
          }
  
          application.registerForRemoteNotifications()
      }
  </code></pre>
  
  <p>Call 3:    </p>
  
  <pre><code>    // remote notification
      func application(_ application: UIApplication, didRegisterForRemoteNotificationsWithDeviceToken deviceToken: Data) {
          ....Some Code....
      }
  </code></pre>
  
  <p>But <strong>below function is not called</strong>.
  But if <strong>app is running in background</strong> then below function is called and <strong>all works fine OTHERWISE App comes to foreground and chat does not after that</strong>.</p>
  
  <pre><code>    // action buttons in enhanced Notification
      @available(iOS 10, *)
      func userNotificationCenter(_ center: UNUserNotificationCenter, didReceive response: UNNotificationResponse, withCompletionHandler completionHandler: () -&gt; Void) {
          guard let action = Constants.ActionType(rawValue: response.actionIdentifier) else {
              completionHandler()
              return
          }
          switch action {
          case .CHAT:
              _ = self.handleRemoteUrl(NSURL(string: "chat") as? URL)
          default:
              _ = self.handleRemoteUrl(NSURL(string: "chat") as? URL)
          }
          completionHandler()
      }
  
      @available(iOS 10.0, *)
      func userNotificationCenter(_ center: UNUserNotificationCenter, willPresent notification: UNNotification, withCompletionHandler completionHandler: (UNNotificationPresentationOptions) -&gt; Void) {
          completionHandler([.alert, .sound])
      }
  }
  </code></pre>
  
  <p>This function is never called may be because it's depreciated in iOS 10 over userNotificationCenter(), not sure. Please explain this also..</p>
  
  <pre><code>    func application(_ application: UIApplication, didReceiveRemoteNotification userInfo: [NSObject : AnyObject]) {
          ....Some Code....
      }
  </code></pre>
  
  <p><strong>I am using iPhone 6s iOS 10 as debugging device.</strong>
  <strong>XCode 8 beta-3</strong></p>