Add socketio test server

Usage:
1. npm install socket.io
2. node test-server.js

react/test-server.js

+const server = require('http').createServer();
+const io = require('socket.io')(server);
+
+// in seconds
+const creationTime = 2.5;
+
+io.on('connection', socket => {
+  console.log('A client has connected - ID: ' + socket.id);
+  socket.send('io connected');
+
+  socket.on('join_room', data => {
+    console.log("Join_room:")
+    console.log(data);
+
+    let room = data.username;
+
+    socket.join(room);
+
+    console.log(socket.rooms)
+    console.log(socket.id+ " has joined room: " + room);
+    io.in(room).clients((err, clients) => {
+      console.log("clients:\n" + clients);
+      socket.send('Room \'' + room + '\' has ' + clients.length + ' user(s)')
+    });
+    socket.send('room \'' + room + '\' joined');
+  });
+
+  socket.on('request', data => {
+    console.log('requested')
+    console.log(data);
+
+    let room = data.username;
+
+    socket.to(room).emit('requested');
+
+    setTimeout(() => {
+      console.log(socket.rooms)
+      io.to(room).emit('created');
+    }, creationTime * 1000);
+  });
+
+  socket.on('disconnect', () => {
+    console.log('disconnect');
+  });
+});
+
+server.listen(5000, () => {
+  console.log('listening on *.5000');
+});