title: rails-api authentication by header's token
body: <p>I'd like to work with <strong>rails-api</strong> gem special to create API-only application. To provide authentication mechanism I want to use built-in <strong>authenticate_or_request_with_http_token</strong> method described in <a href="http://railscasts.com/episodes/352-securing-an-api" rel="noreferrer">Railscasts #352</a>, but   this method in missing here.</p>
  
  <p>Does anybody have an experience with on <strong>rails-api</strong> gem?</p>
  
  <p>P.S. I can see <a href="https://github.com/rails-api/rails-api/issues/29" rel="noreferrer">this approach</a>, but is this  production-ready?</p>