[ios] set initial viewcontroller in appdelegate - swift

Open a viewcontroller with SWRevealViewController From App delegate.

 self.window = UIWindow(frame: UIScreen.main.bounds)
 let storyboard = UIStoryboard(name: "StoryboardName", bundle: nil)
 let swrevealviewcontroller:SWRevealViewController = storyboard.instantiateInitialViewController() as! SWRevealViewController 
 self.window?.rootViewController = swrevealviewcontroller
 self.window?.makeKeyAndVisible()