mocha@2.5.0 breaks build 🚨 (#1917)

* chore(package): update mocha to version 2.5.0

https://greenkeeper.io/

* fix(package): bump mocha to 2.5.1

[skip ci]

Author: greenkeeperio-bot

package.json

@@ -77,7 +77,7 @@
     "lazypipe": "^1.0.1",
     "merge-stream": "^1.0.0",
     "minimatch": "^3.0.0",
-    "mocha": "^2.2.5",
+    "mocha": "^2.5.1",
     "q": "^1.0.1",
     "recursive-readdir": "^2.0.0",
     "run-sequence": "^1.2.0",