chore(deps): bump webpack-sources from 3.2.3 to 3.3.0

Bumps [webpack-sources](https://github.com/webpack/webpack-sources) from 3.2.3 to 3.3.0.
- [Release notes](https://github.com/webpack/webpack-sources/releases)
- [Commits](webpack/webpack-sources@v3.2.3...v3.3.0)

---
updated-dependencies:
- dependency-name: webpack-sources
  dependency-version: 3.3.0
  dependency-type: direct:production
  update-type: version-update:semver-minor
...

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

Author: dependabot[bot]