chore(package): update commitizen to version 4.0.4

Closes #176

Author: greenkeeper[bot]

package.json

@@ -73,7 +73,7 @@
     "babel-eslint": "^8.2.3",
     "babel-jest": "^23.0.1",
     "chai": "^4.1.2",
-    "commitizen": "^2.9.6",
+    "commitizen": "^4.0.4",
     "cz-conventional-changelog": "^2.1.0",
     "enzyme": "^3.3.0",
     "enzyme-adapter-react-16": "^1.1.1",