title: Unlinking a locally cloned repository from its GitHub origin
body: <p>I had a GitHub repository which I decided to delete but continue to maintain only as a local repo on my hard drive. I am now left with the locally cloned repo which maintains all the history and that's fine. However, a number of configuration settings remain that point to the (now deleted) GitHub repo.
  E.g:</p>
  
  <pre><code>$ grep github .git/*
  .git/config:    url = https://github.com/foo/bar.git
  .git/FETCH_HEAD:07c0bac92a829f3acb4b2f5c112de5f787f046e4        branch 'master' of https://github.com/foo/bar
  </code></pre>
  
  <p>What should I do to ensure that my local repo contains no dangling references and that I cannot push upstream from it anymore nor fetch into it? (how do we call such a repo that doesn't have a remote origin?)
  It is not clear to me which settings to delete / update and which values to use.</p>