build(deps-dev): bump webpack-cli from 3.3.2 to 3.3.4

Bumps [webpack-cli](https://github.com/webpack/webpack-cli) from 3.3.2 to 3.3.4.
- [Release notes](https://github.com/webpack/webpack-cli/releases)
- [Changelog](https://github.com/webpack/webpack-cli/blob/master/CHANGELOG.md)
- [Commits](webpack/webpack-cli@v3.3.2...v3.3.4)

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