title: How to disable fork on private repo on github
body: <p>It was easy on bitbucket. if I dont want my repo to be forked. I can disable it. Only people I have invite can work on repo as long as they have permission on repo.</p>
  
  <p>But where is that functionality in github. I have enterprise repo and I want invite people work on it. but dont want them to fork it. </p>
  
  <p>I might have missed something, google search didn't bring anything useful. 
  Can anybody point me in right direction please ? </p>
  
  <p>Thanks in advance for your time.</p>