title: Can't push or pull to Github
body: <p>When I try and pull:</p>
  
  <pre><code>error: cannot open .git/FETCH_HEAD: Permission denied
  </code></pre>
  
  <p>When I try a push or a <code>push -u origin master</code>:</p>
  
  <pre><code>master -&gt; master (non-fast-forward)
  error: failed to push some refs to 'git@github.com:xxxxxxxx/xxxxxxxxxx.git'
  To prevent you from losing history, non-fast-forward updates were rejected
  Merge the remote changes before pushing again.  See the 'Note about
  -forwards' section of 'git push --help' for details.
  </code></pre>