chore(package): update cz-conventional-changelog to version 3.1.1

Closes #40

Author: greenkeeper[bot]

package.json

@@ -73,7 +73,7 @@
     "chai": "^4.1.2",
     "codecov": "^3.0.0",
     "commitplease": "^3.1.0",
-    "cz-conventional-changelog": "^2.0.0",
+    "cz-conventional-changelog": "^3.1.1",
     "eslint": "^5.0.0",
     "husky": "^1.0.0",
     "mocha": "^6.0.0",