app.js

app.post('/message', function(req, res, next) {
  // Use the REST client to send a text message
  client.messages.create({
    to: req.body.to,
    from: TWILIO_PHONE_NUMBER,
    body: 'Good luck on your Twilio quest!'
  }).then(function(message) {
    // When we get a response from Twilio, respond to the HTTP POST request
    res.send('Message is inbound!');
  }).catch(function(error) {
    console.log(error);
  }) ;
});