Merge pull request #3 from inspekter/greenkeeper/mocha-4.0.0

Update mocha to the latest version 🚀

Author: pablomdo

package.json

@@ -24,7 +24,7 @@
   },
   "devDependencies": {
     "chai": "^4.1.2",
-    "mocha": "^3.5.3",
+    "mocha": "^4.0.0",
     "standard": "^10.0.3"
   }
 }