title: how to keep ngrok alive after mac mini goes to sleep
body: <p>I setup ngrok on a mac mini so that it can act as a build machine for ios.  So when somebody merges in github it will trigger a webhook that will kick off a jenkins build on the mac mini.  However, when the machine goes to sleep and I try to navigate to the jenkins instance I get an error </p>
  
  <pre><code>Tunnel XXXXXXXX.ngrok.io not found
  </code></pre>
  
  <p>Is there something I need to do to keep the connection alive?</p>