chore(package): update commitizen to version 4.0.3

Closes #15

Author: greenkeeper[bot]

package.json

@@ -24,7 +24,7 @@
     "@babel/preset-env": "^7.1.0",
     "babel-core": "^7.0.0-bridge.0",
     "babel-jest": "^23.6.0",
-    "commitizen": "^3.0.4",
+    "commitizen": "^4.0.3",
     "coveralls": "^3.0.2",
     "cz-conventional-changelog": "^2.1.0",
     "eslint": "^5.9.0",