Bump webpack-cli from 3.3.2 to 4.1.0

Bumps [webpack-cli](https://github.com/webpack/webpack-cli) from 3.3.2 to 4.1.0.
- [Release notes](https://github.com/webpack/webpack-cli/releases)
- [Changelog](https://github.com/webpack/webpack-cli/blob/master/CHANGELOG.md)
- [Commits](https://github.com/webpack/webpack-cli/compare/v3.3.2...webpack-cli@4.1.0)

Signed-off-by: dependabot-preview[bot] <support@dependabot.com>

package.json

@@ -59,6 +59,6 @@
     "mocha-lcov-reporter": "^1.3.0",
     "standard": "^13.0.1",
     "webpack": "^4.32.2",
-    "webpack-cli": "^3.3.2"
+    "webpack-cli": "^4.1.0"
   }
 }