chore(package): update mocha to version 2.5.1

https://greenkeeper.io/

Author: greenkeeperio-bot

package.json

@@ -41,7 +41,7 @@
     "eslint": "^2.9.0",
     "eslint-config-toboid": "^1.0.1",
     "lodash": "^4.8.2",
-    "mocha": "^2.4.5",
+    "mocha": "^2.5.1",
     "nyc": "^6.4.0"
   }
 }