title: Google Cloud Print API: User credentials required
body: <p>I'm trying to use the Google Cloud Print library to get a list of the cloud printers available to the users, but when I do a request I get an error: "User credentials required"</p>
  
  <p>This is how I send the request:</p>
  
  <pre><code>var request = require('request');
  
  var options = {
      url: 'https://www.google.com/cloudprint/search',
      headers: {
              'X-CloudPrint-Proxy': 'APP_NAME',
              'Authorization': 'GoogleLogin auth=ACCESS_TOKEN_HERE'
      }
  };
  
  function callback(err, response, body) {
      console.log(err);
      console.log(response);
      console.log(body);
  }
  
  request(options, callback);
  </code></pre>