Merge pull request #63 from akikoo/greenkeeper/mocha-4.0.0

Update mocha to the latest version 🚀

Author: akikoo

package.json

@@ -21,7 +21,7 @@
     "babel-preset-es2015": "^6.16.0",
     "babel-preset-react": "^6.16.0",
     "jsdom": "^11.0.0",
-    "mocha": "^3.4.0",
+    "mocha": "^4.0.0",
     "sinon": "^4.0.0",
     "unexpected": "^10.18.0",
     "unexpected-sinon": "^10.1.1"