text: const express = require('express');
  const spdy = require('spdy');
  const fs = require('fs');
  
  const app = express();
  
  app.get('/', function (req, res) {
    res.send('Serving using HTTP2!');
  });
  
  const options = {
    key: fs.readFileSync(__dirname + '/../certificate/server.key'),
    cert:  fs.readFileSync(__dirname + '/../certificate/server.crt')
  };
  
  spdy
    .createServer(options, app)
    .listen(3000, (err) => {
      if (err) {
        throw new Error(err);
      }
  
      console.log('Listening on port: ' + 3000 + '.');
    });