chore(package): update webpack-cli to version 3.3.9

Closes #54

Author: greenkeeper[bot]

package.json

@@ -42,7 +42,7 @@
     "typescript": "^3.4.5",
     "uglifyjs-webpack-plugin": "^2.1.3",
     "webpack": "4.32.0",
-    "webpack-cli": "3.3.2",
+    "webpack-cli": "3.3.9",
     "webpack-dev-server": "3.4.1"
   },
   "dependencies": {