title: Pushing to UINavigationViewController
body: <p>I'm doing a login view, which retrieves data and when everything goes well it should move from Login View (UIViewController) to the Navigation controller(UINavigationController) which in his turn should serve as root view controller and move the user to the main view(UIViewController).
  The problem is when i reach to the code that works just fine with me inside other classes, it does nothing here, not even throwing exceptions to handle here's my code </p>
  
  <pre><code>   func moveToMainView(){
      let navigationControllerView = self.storyboard?.instantiateViewControllerWithIdentifier("NavControllerView") as! UINavigationController
  
      self.navigationController?.pushViewController(navigationControllerView, animated: true)
  
  }
  </code></pre>
  
  <p>I searched to find if there any special case for UINavigationController, but no luck so far... hope you can help me </p>