title: 'recordingStatusCallback' doesn't get triggered
body: <p>In the next code everything goes as expected except <strong>recordingStatusCallback</strong> URL is never called when the record is available:</p>
  
  <pre><code>&lt;?xml version="1.0" encoding="UTF-8"?&gt;
  &lt;Response&gt;
     &lt;Say&gt;Before calling {{To}}&lt;/Say&gt;
        &lt;Dial                      
           recordingStatusCallbackMethod="POST"
           recordingStatusCallbackEvent="completed"
           record="true" 
           trim="trim-silence" 
           recordingStatusCallback="https://ourdomain.com/ourapp/twCallService/recordingStatusCallBack"&gt;
           &lt;Number
              statusCallbackMethod="POST"
              statusCallbackEvent="completed"
              statusCallback="https://ourdomain.com/ourapp/twCallService/statusCallBack"&gt;
              {{To}}
           &lt;/Number&gt;
        &lt;/Dial&gt;
     &lt;Say&gt;After calling {{To}}&lt;/Say&gt;
  &lt;/Response&gt;         
  </code></pre>
  
  <p>Also "<strong>trim-silence</strong>" seems not to work.</p>
  
  <p>¿Does somebody know what happens here?</p>
  
  <p>Note that record atribute is properly set to true.</p>
  
  <p>Thanks!</p>