title: --set-upstream track/pull a new branch from remote with forward slash "/" in the branch name
body: <p>I have a branch on my remote which my local repo does not know about. I'm trying to create the branch locally, track and pull, but the branch has a forward slash in it's name.</p>
  
  <p>My results:</p>
  
  <pre><code>$ git branch --set-upstream feature/users origin/feature/users
  fatal: Not a valid object name: 'origin/feature/users' 
  </code></pre>
  
  <p>Do I need to escape the forward slash in the branch name? I've tried quotes as well as backslash. </p>