title: Facebook SDK kicks to Safari rather than to the app (Swift)
body: <p>I'm relatively new to programming and am coding an app that involves users registering in facebook. Whenever I press the facebook login it kicks me out to safari and kicks me back when I login. I understand the app store requires you to login without switching applications for usability, is there anyway to prevent this? When I exit the app, it seems my token is not stored and I have to log back in. I have looked through stack overflow and all the answers seemed to be in objective c and over 2 years old. I have also updated to ios 9, so this may be part of the issue. Here's my view controller code below where I create the button and add it to the vc.</p>
  
  <pre><code>func loginButton(loginButton: FBSDKLoginButton!, didCompleteWithResult result:       FBSDKLoginManagerLoginResult!, error: NSError!) {
      if (error == nil) {
          println("Login complete")
      } else {
          println(error.localizedDescription)
      }
  }
  
  func loginButtonDidLogOut(loginButton: FBSDKLoginButton!) {
      println("User logged out...")
  }
  
  override func viewDidLoad() {
      super.viewDidLoad()
  
      if (FBSDKAccessToken.currentAccessToken() == nil) {
          println("Not logged in...")
      } else {
          println("Logged in...")
      }
  
      var loginButton = FBSDKLoginButton()
      loginButton.readPermissions = ["public_profile", "email", "user_friends"]
      loginButton.center = self.view.center
      loginButton.delegate = self
      self.view.addSubview(loginButton)
  }
  </code></pre>