fix(deps): freeze socket.io version

socket.io@1.4.8 breaks IE <= 9 compat, this freezes the version until socketio/engine.io#407 is resolved.

package.json

@@ -303,7 +303,7 @@
     "optimist": "^0.6.1",
     "qjobs": "^1.1.4",
     "rimraf": "^2.3.3",
-    "socket.io": "^1.4.5",
+    "socket.io": "1.4.7",
     "source-map": "^0.5.3",
     "tmp": "0.0.28",
     "useragent": "^2.1.9"