chore(package): update mocha to version 3.3.0 (#6)

https://greenkeeper.io/

Author: greenkeeper[bot]

package.json

@@ -27,7 +27,7 @@
   "devDependencies": {
     "assume": "~1.5.0",
     "istanbul": "0.4.x",
-    "mocha": "~3.2.0",
+    "mocha": "~3.3.0",
     "pre-commit": "~1.2.0"
   }
 }