fix(package): update mongoose to version 4.11.0

Author: greenkeeper[bot]

package.json

@@ -28,7 +28,7 @@
     "express-session": "~1.15.1",
     "forever": "~0.15.1",
     "method-override": "~2.3.5",
-    "mongoose": "~4.10.4",
+    "mongoose": "~4.11.0",
     "mongoose-user": "~0.0.1",
     "morgan": "~1.8.1",
     "passport": "~0.3.2",