Permite desplegar el bot en la plataforma de Heroku

express.js

/* BEGIN: fix deployment into heroku*/
const PORT = process.env.PORT || 3000;
const INDEX = '/docs/index.html';

let express = require('express');
//res.sendFile(INDEX, { root: __dirname })
const server = express()
    .use((req, res) => res.sendFile(INDEX, { root: __dirname }))
    .listen(PORT, () => logger.info(`Listening on ${PORT}`));
/* END: fix deployment into heroku*/