title: 'OpenExternalURLOptionsKey' is not a member type of 'UIApplication' Auth0 problem
body: <p>I have trouble with importing Auth0 into my project I'm using Cocoa pods and have installed Auth0 as one then I import the Auth0 library into my app delegate. This then needs you to import a function into your app delegate and when I do this I get the problem that OpenExternalURLOptionsKey' is not a member type of 'UIApplication' and I do not see the trouble here qua the Auth0 cocoa pods installation did work.</p>
  
  <p>I've already tried reinstalling the cocoapod in the podfile and I do not see where the other problem lies so do not know where I should start problem-solving. </p>
  
  <pre><code>import UIKit
  import CoreData
  import Auth0
  
  @UIApplicationMain
  class AppDelegate: UIResponder, UIApplicationDelegate {
  
      var window: UIWindow?
      func application(_ application: UIApplication, didFinishLaunchingWithOptions launchOptions: [UIApplicationLaunchOptionsKey: Any]?) -&gt; Bool {
          // Override point for customization after application launch.
          return true
      }
  
      func applicationWillResignActive(_ application: UIApplication) {
          // Sent when the application is about to move from active to inactive state. This can occur for certain types of temporary interruptions (such as an incoming phone call or SMS message) or when the user quits the application and it begins the transition to the background state.
          // Use this method to pause ongoing tasks, disable timers, and invalidate graphics rendering callbacks. Games should use this method to pause the game.
      }
  
      func applicationDidEnterBackground(_ application: UIApplication) {
          // Use this method to release shared resources, save user data, invalidate timers, and store enough application state information to restore your application to its current state in case it is terminated later.
          // If your application supports background execution, this method is called instead of applicationWillTerminate: when the user quits.
      }
  
      func applicationWillEnterForeground(_ application: UIApplication) {
          // Called as part of the transition from the background to the active state; here you can undo many of the changes made on entering the background.
      }
  
      func applicationDidBecomeActive(_ application: UIApplication) {
          // Restart any tasks that were paused (or not yet started) while the application was inactive. If the application was previously in the background, optionally refresh the user interface.
      }
  
      func applicationWillTerminate(_ application: UIApplication) {
          // Called when the application is about to terminate. Save data if appropriate. See also applicationDidEnterBackground:.
          // Saves changes in the application's managed object context before the application terminates.
          self.saveContext()
      }
      func application(_ app: UIApplication, open url: URL, options: [UIApplication.OpenExternalURLOptionsKey : Any]) -&gt; Bool {
          return Auth0.resumeAuth(url, options: options)
      }
  </code></pre>
  
  <p>I'm trying to make a twitch sign in plausible in my app</p>