title: hold time and talk time with twilio
body: <p>I am using twilio in my rails 3.2 application.</p>
  
  <p>I am forwarding inbound calls with Dial verb, 
  I need to determine:</p>
  
  <p>1) The total hold time</p>
  
  <p>2) The total talk time</p>
  
  <p>of a particular call for billing purpose.</p>
  
  <p>Is it possible with twilio?</p>