Bump webpack-cli from 2.1.5 to 3.0.8

Bumps [webpack-cli](https://github.com/webpack/webpack-cli) from 2.1.5 to 3.0.8.
- [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/v2.1.5...v3.0.8)

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

package.json

@@ -13,7 +13,7 @@
     "ts-loader": "^4.4.2",
     "typescript": "^2.7.2",
     "webpack": "^4.15.1",
-    "webpack-cli": "^2.0.10",
+    "webpack-cli": "^3.0.8",
     "webpack-dev-server": "^3.1.4",
     "babel-eslint": "^8.2.5"
   }