refator: remove old node fix (#203)

Only node 10 is supported for a long time. The fix for node < 10 can be
removed.

Author: TrySound

lib/server.js

@@ -9,7 +9,7 @@
   included in all copies or substantial portions of this Source Code Form.
 */
 const url = require('url');
-const { createServer, ServerResponse } = require('http');
+const { createServer } = require('http');
 
 const open = require('open');
 
@@ -96,12 +96,6 @@ const start = async function start() {
     }
   };
 
-  // Node < v10 doesn't send upgrade requests through. This simulates what occurs on
-  // on Node >= v10
-  if (parseInt(process.versions.node, 10) < 10) {
-    server.on('upgrade', (req) => server.emit('request', req, new ServerResponse(req)));
-  }
-
   this.listening = true;
 
   const protocol = secure ? 'https' : 'http';