Fix the engine.io version

package.json

@@ -17,8 +17,8 @@
         "debug": "~0.7.4",
         "ejs": "~1.0.0",
         "emmet": "git://github.com/cloud9ide/emmet-core.git#2ff6dc06ad",
-        "engine.io": "^1.6.9",
-        "engine.io-client": "^1.6.9",
+        "engine.io": "1.6.9",
+        "engine.io-client": "1.6.9",
         "jsonm": "1.0.6",
         "http-error": "~0.0.5",
         "less": "^2.4.0",