title: Change Navigation Bar Attributes in Only One ViewController
body: <p>I have an application's navigation bar set in the <code>AppDelegate</code>.
  In one of my <code>ViewController's</code> I'm trying to set the attributes differently  - they work however when I get to other VC's the still persist.</p>
  
  <p>What is the correct way to implement this?</p>
  
  <p>AppDelegate.swift</p>
  
  <pre><code>UINavigationBar.appearance().titleTextAttributes = [
          NSFontAttributeName: UIFont(name: "MuseoSans-500", size: 19)!,
          NSForegroundColorAttributeName: UIColor.white
      ]
      UINavigationBar.appearance().tintColor = UIColor.white
  </code></pre>
  
  <p>SharkViewController.swift</p>
  
  <pre><code>// MARK: - View Did Load
  override func viewDidLoad() {
      super.viewDidLoad()
  
      UINavigationBar.appearance().titleTextAttributes = [
          NSFontAttributeName: UIFont(name: "MuseoSans-500", size: 19)!,
          NSForegroundColorAttributeName: UIColor.black
      ]
  }
  </code></pre>