code: function(params, callback) {
        if (!params.url) return (callback || function() {})(new Error(utils.i18n.webhooks.url));
        if (!params.events || !params.events.length) return (callback  || function() {})(new Error(utils.i18n.webhooks.events));
        if (!params.secret) return (callback  || function() {})(new Error(utils.i18n.webhooks.secret));
  
        utils.debug('Webhooks register: ' + params.url);
        request.post({
          path: '/webhooks',
          body: {
            target_url: params.url,
            events: params.events,
            secret: params.secret,
            config: params.config || {},
  	        version: version,
          }
        }, function(err, res) {
          if (!err) res.body.secret = params.secret;
          if (callback) callback(err, res);
        });
      }
docs: Register a Webhook
  
  @param  {Object}   params
  @param  {String[]} params.events      Array of event names to subscribe to
  @param  {String}   params.url             URL for webhook events to go to
  @param  {String}   params.secret          Unique string known only to your server for validating webhook events
  @param  {Object}   params.config          JSON object to send with all webhook events
  @param  {Function} callback               Callback function