chore(package): update @commitlint/config-conventional to version 8.3.4

Closes #54

Author: greenkeeper[bot]

package.json

@@ -53,7 +53,7 @@
   },
   "devDependencies": {
     "@commitlint/cli": "^8.3.4",
-    "@commitlint/config-conventional": "^7.1.2",
+    "@commitlint/config-conventional": "^8.3.4",
     "eslint": "^5.6.0",
     "eslint-config-prettier": "^3.1.0",
     "eslint-config-standard": "^12.0.0",