title: Open two different ports in Heroku app
body: <p>I'm currently using botkit-sms with Node and Express, deployed on Heroku to create a mobile application that can send SMS messages to users who aren't yet signed up. In my <code>server.js</code> file, I open ports for the API and the messaging bot, which works locally but breaks when I deploy to Heroku. I get the error <code>Error: listen EADDRINUSE :::56136</code>. I know this is because both are trying to use process.env.PORT. Is there a way I can fix this?</p>
  
  <p>Relevant code:</p>
  
  <pre><code>import express from 'express';
  
  const app = express();
  
  const TwilioSMSBot = require('botkit-sms')
  const controller = TwilioSMSBot({
    account_sid: ACCOUNT_ID,
    auth_token: AUTH_TOKEN,
    twilio_number: TWILIO_NUMBER
  })
  
  const port = process.env.PORT || 9090;
  app.listen(port);
  
  app.get('/', (req, res) =&gt; {
    res.send('hi');
  });
  
  let bot = controller.spawn({})
  
  controller.setupWebserver(process.env.PORT ||  3001, function (err, webserver) {
    controller.createWebhookEndpoints(controller.webserver, bot, function () {
      console.log('TwilioSMSBot is online!')
    })
  })
  </code></pre>