update mongoose version

package.json

@@ -8,7 +8,7 @@
     "babel-preset-stage-2": "^6.24.1",
     "express": "^4.13.1",
     "express-partials": "^0.3.0",
-    "mongoose": "^4.8.5",
+    "mongoose": "~4.13.12",
     "async": "^2.1.5",
     "connect-mongo": "^1.3.2",
     "cookie-parser": "~1.4.3",