chore(package): update cz-conventional-changelog to version 3.1.0

Closes #306

Author: greenkeeper[bot]

package.json

@@ -91,7 +91,7 @@
     "commitizen": "^3.0.0",
     "coveralls": "^3.0.2",
     "cross-env": "^5.2.0",
-    "cz-conventional-changelog": "^2.1.0",
+    "cz-conventional-changelog": "^3.1.0",
     "husky": "^1.0.1",
     "jest": "^23.6.0",
     "jest-config": "^23.6.0",