Update package.json

Fix security Issue

Author: Pelirrojo

P04_WebApplication/server/package.json

@@ -5,7 +5,7 @@
         "socket.io": ">= 0.9.16",
         "q"        : ">= 0.9.7",
         "mongodb"  : ">= 1.3.5",
-        "express"  : "3.4.0"
+        "express"  : ">=3.11.0"
     },
 
     "repository": {