title: Block a git branch from being pushed
body: <p>Here's the situation:</p>
  
  <p>I have a public repository for my open-source app on github.com. However, now I'd like to write some specific code that will not be public (I might use it in a commercial version of my application).</p>
  
  <p>I figured I could use the same repository, and I'd create a "private" branch in my git repository that I wouldn't push.</p>
  
  <p>But, mistakes happen. Is there some way to forbid git from ever pushing a branch to remote servers?</p>
  
  <p>If there's a better way to handle this situation, I would of course welcome any suggestions.</p>