title: How do I parse URLs in the format of /id/123 not ?foo=bar
body: <p>I'm trying to parse an URL like:</p>
  <p><a href="http://example.com/id/123" rel="nofollow noreferrer">http://example.com/id/123</a></p>
  <p>I've read through the <code>net/url</code> docs but it seems like it only parses strings like</p>
  <p><a href="http://example.com/blah?id=123" rel="nofollow noreferrer">http://example.com/blah?id=123</a></p>
  <p>How can I parse the ID so I end up with the value of the id in the first example?</p>
  <p>This is not one of my own routes but a http string returned from an openid request.</p>