title: Why do I have so many simulators and how do I restore the basic platforms?
body: <p>Environment: Xcode v6.4
  <p>
  I just noticed that I have too may simulators.<br>
  <br/>
  Why has this happened and how do I control it?</p>
  
  <p><img src="https://i.stack.imgur.com/D9wLH.png" alt="enter image description here"></p>