chore(package): update mocha to version 3.4.1

Closes #6

package.json

@@ -32,7 +32,7 @@
   "devDependencies": {
     "concat-stream": "~1.6.0",
     "istanbul": "~0.4.5",
-    "mocha": "~3.3.0",
+    "mocha": "~3.4.1",
     "pre-commit": "~1.2.0"
   }
 }