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

Closes #28

Author: greenkeeper[bot]

package.json

@@ -26,7 +26,7 @@
   },
   "homepage": "https://github.com/beogip/vault-dotenv#readme",
   "devDependencies": {
-    "cz-conventional-changelog": "^2.1.0",
+    "cz-conventional-changelog": "^3.1.0",
     "eslint": "^5.15.3",
     "semantic-release": "^15.1.7",
     "standard": "^12.0.0"