chore(package): update commitizen to version 4.1.0

Closes #81

Author: greenkeeper[bot]

package.json

@@ -58,7 +58,7 @@
     "babel-preset-react": "^6.16.0",
     "babel-preset-stage-0": "^6.16.0",
     "babel-register": "^6.16.3",
-    "commitizen": "^2.8.6",
+    "commitizen": "^4.1.0",
     "conventional-changelog-cli": "^1.2.0",
     "coveralls": "^2.13.1",
     "cz-conventional-changelog": "^2.0.0",