chore(package): update mocha to version 2.4.2

http://greenkeeper.io/

Author: greenkeeperio-bot

package.json

@@ -58,7 +58,7 @@
     "coveralls": "2.11.6",
     "eslint": "1.10.3",
     "istanbul": "0.4.2",
-    "mocha": "2.3.4",
+    "mocha": "2.4.2",
     "npm-run-all": "1.5.0",
     "uglifyify": "3.0.1",
     "utf8-length": "0.0.1",