title: Can't install older version 1.8.27 of Geth on Ubuntu 16.04
body: <p>I have tried</p>
  <pre><code>sudo apt-get install ethereum
  
  sudo apt-get install ethereum=VERSION
  </code></pre>
  <p>And</p>
  <pre><code>sudo apt-get upgrade ethereum
  </code></pre>
  <p>To install a specific version of Geth but I can't.</p>