chore(deps): update commitlint monorepo to v8 (#412)

Author: renovate[bot]

package-lock.json

@@ -40,8 +40,8 @@
     "@babel/cli": "7.4.4",
     "@babel/core": "7.4.5",
     "@babel/preset-env": "7.4.5",
-    "@commitlint/cli": "7.6.1",
-    "@commitlint/config-conventional": "7.6.0",
+    "@commitlint/cli": "8.0.0",
+    "@commitlint/config-conventional": "8.0.0",
     "@webpack-contrib/defaults": "4.1.1",
     "@webpack-contrib/eslint-config-webpack": "3.0.0",
     "babel-jest": "24.8.0",