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

Closes #16

Author: greenkeeper[bot]

package.json

@@ -26,7 +26,7 @@
     "babel-jest": "^23.6.0",
     "commitizen": "^3.0.4",
     "coveralls": "^3.0.2",
-    "cz-conventional-changelog": "^2.1.0",
+    "cz-conventional-changelog": "^3.1.0",
     "eslint": "^5.9.0",
     "eslint-config-prettier": "^3.3.0",
     "eslint-plugin-prettier": "^3.0.0",