remove previous SockJS implementation, and move example to WebSocket test

javascript/ql/test/library-tests/frameworks/WebSocket/sockjs.js

@@ -0,0 +1,16 @@
+const express = require('express');
+const http = require('http');
+const sockjs = require('sockjs');
+
+const app = express();
+const server = http.createServer(app);
+const sockjs_echo = sockjs.createServer({});
+sockjs_echo.on('connection', function(conn) {
+    conn.on('data', function(message) {
+        var data = JSON.parse(message);
+        conn.write(JSON.stringify(eval(data.test)));
+    });
+});
+
+sockjs_echo.installHandlers(server, {prefix:'/echo'});
+server.listen(9090, '127.0.0.1');