title: Ruby open-uri proxy authentication fails
body: <p>I'm coding a native Ruby script to scrap a website using Nokogiri, whenever I pass proxy options to the open-uri <code>open()</code> method, it returns <code>407 Proxy Authentication Required</code> but my options does have the authentification details, here's my code</p>
  
  <pre><code>proxy_url = URI.parse("http://12.34.567.89:PORT")
  session = Nokogiri::HTML(open("http://google.com", :proxy_http_basic_authentication =&gt;[proxy_url, "username", "password"]
  </code></pre>
  
  <p>Note: As my proxy is premium, I have replaced real proxy credentials with fake one</p>