title: Xcode 8 :function types cannot have argument label breaking my build
body: <p>It seems that for some reason Swift have chosen to make coding in it less readable by forcing users to remove completion handler parameter labels.  I have read the Swift discussion and still think it's a mistake.  At least they could have made it optional. </p>
  
  <p>When building using Xcode 8 - is there a way to force the compiler to use Swift 2.3 so I don't get these errors anymore? 
  I have updated the option to use legacy Swift (under build settings) 
  <a href="https://i.stack.imgur.com/A4WlH.jpg"><img src="https://i.stack.imgur.com/A4WlH.jpg" alt="legacy support in xcode"></a>
  but I still seem to get this error: </p>
  
  <blockquote>
    <p>Function types cannot have argument label 'isloggedIn'; use '_'
    instead</p>
  </blockquote>
  
  <p><a href="https://i.stack.imgur.com/zZKtZ.jpg"><img src="https://i.stack.imgur.com/zZKtZ.jpg" alt="error Xcode 8"></a></p>
  
  <p>How can I keep my labels in my completion handlers?</p>