code: function options(req, res) {
    res.__apiMethod = 'options';
    res.status(200);
    res.json(this.urls());
  }
docs: options - controller that returns urls
  
  @param  {express.Request}  req        the http(s) request
  @param  {express.Response} res        the http(s) response
  @param  {Function}         next       the callback should be called if controller fails
  
  @memberof ModelAPIRouter