chore(package): update mocha to version 2.5.1

https://greenkeeper.io/

Author: greenkeeperio-bot

Diff for: package.json

@@ -51,7 +51,7 @@
     "electron-packager": "7.0.2",
     "electron-prebuilt": "1.1.1",
     "electron-rebuild": "1.1.4",
-    "mocha": "2.4.5",
+    "mocha": "2.5.1",
     "node-gyp": "3.3.1",
     "node-sass": "3.7.0",
     "npm-check-updates": "2.6.5",