message: Add an example of how to use fb insights api
diff: @@ -488,6 +488,15 @@ controller.hears(['send tagged message'], 'message_received', function (bot, mes
  bot.reply(message, taggedMessage);
  });
  +controller.hears(['insights'], 'message_received', function (bot, message) {
  + controller.api.insights.get_insights(['page_messages_active_threads_unique', 'page_messages_blocked_conversations_unique'], null, null, function (err, body) {
  + if (err) {
  + bot.reply(message, 'Insights error');
  + } else {
  + bot.reply(message, JSON.stringify(body.data));
  + }
  + });
  +});
  function formatUptime(uptime) {
  var unit = 'second';
  