title: OpenEdx native installation fails
body: <p>I was trying to install OpenEdx (ginkgo 2) on an Ubuntu system following this guide : <a href="https://openedx.atlassian.net/wiki/spaces/OpenOPS/pages/146440579/Native%2BOpen%2BedX%2BUbuntu%2B16.04%2B64%2Bbit%2BInstallation" rel="nofollow noreferrer">https://openedx.atlassian.net/wiki/spaces/OpenOPS/pages/146440579/Native%2BOpen%2BedX%2BUbuntu%2B16.04%2B64%2Bbit%2BInstallation</a></p>
  
  <p>The setup continually fails with the following error </p>
  
  <pre><code>fatal: [localhost]: FAILED! =&gt; {"changed": true, "failed": true, "rc": 100, "stderr": "W: The repository 'http://nginx.org/packages/ubuntu xenial Release' does not have a Release file.\nW: http://downloads-distro.mongodb.org/repo/ubuntu-upstart/dists/dist/Release.gpg: Signature by key 492EAFE8CD016A07919F1D2B9ECBEC467F0CEB10 uses weak digest algorithm (SHA1)\nE: Failed to fetch http://nginx.org/packages/ubuntu/dists/xenial/nginx/binary-amd64/Packages  Connection failed [IP: 206.251.255.63 80]\nE: Some index files failed to download. They have been ignored, or old ones used instead.\n", "stdout": "", "stdout_lines": []}
  </code></pre>
  
  <p>It has something to do with repositories but I can't figure out what to do. </p>