title: How to uninstall ruby installed by ruby-install
body: <p>I have many rubies installed by <a href="https://github.com/postmodern/ruby-install">ruby-install</a> under <code>~/.rubies</code>:</p>
  
  <pre><code>ls .rubies
  ruby-1.9.3-p545 ruby-2.0.0-p598 ruby-2.1.3      ruby-2.1.5
  ruby-2.0.0-p451 ruby-2.1.2      ruby-2.1.4      ruby-2.2.0
  </code></pre>
  
  <p>I want to uninstall one of the ruby installed by ruby-install, How do I do that?</p>