title: UISwitch doesn't seem to show the right state
body: <p>I have four UISwitches on a page. 
  Im testing AnimalSwitch to see if it works.
  By default it’s on, when I switch it off and go to a different view controller and back, the test label says it is still switched off, but the switch image shows it is on.
  This is the code of the Switch im trying to change(the others i’ve left untouched until i fix this one). 
  The other switches Are named the same, only the word “Animal” changes. </p>
  
  <pre><code>let defaults = UserDefaults.standard
    AnimalSwitch.setOn(true, animated: true)
    if (defaults.object(forKey: "AnimalswitchState") != nil) {
      AnimalSwitch.isOn = defaults.bool(forKey: "AnimalswitchState")
    print("switched")
  }
  </code></pre>