title: Cannot call value of non-function type '((Selector) -> Bool)!' converting to Swift 3
body: <pre><code>if (model.classForCoder.respondsToSelector("rangeKeyAttribute")) {
      let rangeKeyAttribute = model.classForCoder.rangeKeyAttribute!()
      let index = keys.indexOf(rangeKeyAttribute)
      if let index = index {
          keys.removeAtIndex(index)
          keys.insert(rangeKeyAttribute, atIndex: 0)
      }
  }
  </code></pre>
  
  <p>This code used to work fine, but in Swift 3 the compiler said this is deprecated and this:</p>
  
  <pre><code>if (model.classForCoder.respondsToSelector("rangeKeyAttribute")) {
  </code></pre>
  
  <p>Should be changed to:</p>
  
  <pre><code>if (model.classForCoder.responds(to: #selector(AWSDynamoDBModeling.rangeKeyAttribute))) {
  </code></pre>
  
  <p>Swift 3 doesn't like this and is throwing the error: </p>
  
  <p>Cannot call value of non-function type '((Selector) -> Bool)!'</p>
  
  <p>I can't seem to figure out how to make it Swift 3 acceptable!</p>