title: how to fetch HTTP post request from webhook API in ruby on rails 3.2
body: <p>I am new to ROR. I am developing <code>SMS</code> service for my rails application. The app has to receive an asynchronous <code>HTTP POST request</code> from <code>webhook API</code> and has to generate an auto reply.
  I am working with <code>rails 3.2.13</code>.</p>
  
  <p>Can anyone tell me how to fetch this <code>JSON</code> request in rails?</p>