title: Unable to push to Gitlab, You are not allowed to push code to this project
body: <p>I recently became unable to push any changes to any of my repositories on Gitlab.com.</p>
  
  <p>I know this sometimes happens if you've changed your SSH keys, or the site's down, but as far as I know, I haven't changed anything in my <code>~/.ssh</code> directory, and Gitlab.com appears to be working.</p>
  
  <p>Yet if I run <code>git push</code> I get the error:</p>
  
  <pre><code>You are not allowed to push code to this project.
  fatal: Could not read from remote repository.
  
  Please make sure you have the correct access rights
  and the repository exists.
  </code></pre>
  
  <p>Oddly, <code>git pull</code> still works. I also tried re-cloning the repo, making and commit and pushing, but that still fails. Adding the <code>--verbose</code> option showed no further details.</p>
  
  <p>I double checked that the SSH key on file in my Gitlab account matches the key on file in my <code>~/.ssh/id_rsa.pub</code> file. I also tried adding the entry of my <code>~/.ssh/config</code>:</p>
  
  <pre><code>Host gitlab.com
   IdentityFile ~/.ssh/id_rsa
  </code></pre>
  
  <p>but that had no effect.</p>
  
  <p>What's going on here? Why is Gitlab suddenly not accepting the SSH key on file?</p>