compatibility: add node.js example server

test/compatibility/node/echo_server.js

@@ -0,0 +1,11 @@
+const WebSocket = require('ws');
+
+const wss = new WebSocket.Server({ port: 8080 });
+
+wss.on('connection', function connection(ws) {
+  ws.on('message', function incoming(message) {
+    console.log('received: %s', message);
+  });
+
+  ws.send('something');
+});

test/compatibility/node/echo_server_permessagedeflate.js

@@ -0,0 +1,11 @@
+const WebSocket = require('ws');
+
+const wss = new WebSocket.Server({ port: 8080, perMessageDeflate: true });
+
+wss.on('connection', function connection(ws) {
+  ws.on('message', function incoming(message) {
+    console.log('received: %s', message);
+  });
+
+  ws.send('something');
+});