code: function sendTextMessage(recipientId, textToSend, token) {
        textMessageData = {
          text:textToSend
        }
        request({
          url: FB_MSG_URL,
          qs: {access_token:token},
          method: 'POST',
          json: {
            recipient: {id:recipientId},
            message: textMessageData,
          }
        }, function(error, response, body) {
          if (error) {
            node.log('Error sending text message: ', error);
          } else if (response.body.error) {
            node.log('Error: ', response.body.error);
          }
        });
      }
docs: Send out text message (of msgType: text)