title: Check if two urls are for the same website
body: <p>I'm looking for a way to compare two urls. I can do:</p>
  
  <pre><code>URI('http://www.test.com/blabla').host
  </code></pre>
  
  <p>to have the base name, but this not reliable. For example:</p>
  
  <pre><code>URI('http://www.test.com/blabla').host == URI('http://test.com/blabla').host
  </code></pre>
  
  <p>returns <code>false</code>, but they can be the same site. To have the IP address is not reliable too because if I do:</p>
  
  <pre><code>IPSocket.getaddress(URI('http://hello.herokuapp.com').host) ==
  IPSocket.getaddress(URI('http://test.herokuapp.com').host)
  </code></pre>
  
  <p>It returns <code>true</code>, but they are not the same site. Is there a more reliable way?</p>