Lock socket.io version

Without a specific version in package.json,
this could break without warning in the future...

Author: Rob--W

instant-markdown-d

@@ -112,7 +112,6 @@ function httpHandler(req, res) {
   }
 }
 
-io.set('log level', 1);
 io.sockets.on('connection', function(sock){
   socket = sock;
   process.stdout.write('connection established!');

package.json

@@ -13,6 +13,6 @@
     "highlight.js": "^8.4.0",
     "markdown-it": "^3.0.3",
     "send": "~0.1.0",
-    "socket.io": ""
+    "socket.io": "^1.4.5"
   }
 }