Bump clean-webpack-plugin from 2.0.2 to 4.0.0

Bumps [clean-webpack-plugin](https://github.com/johnagan/clean-webpack-plugin) from 2.0.2 to 4.0.0.
- [Release notes](https://github.com/johnagan/clean-webpack-plugin/releases)
- [Commits](johnagan/clean-webpack-plugin@v2.0.2...v4.0.0)

---
updated-dependencies:
- dependency-name: clean-webpack-plugin
  dependency-type: direct:development
  update-type: version-update:semver-major
...

Signed-off-by: dependabot[bot] <[email protected]>

Author: dependabot[bot]

package-lock.json

@@ -18,7 +18,7 @@
     "angular-mocks": "^1.8",
     "babel-loader": "^9",
     "babel-plugin-angularjs-annotate": "^0.10.0",
-    "clean-webpack-plugin": "^2.0",
+    "clean-webpack-plugin": "^4.0",
     "codecov": "^3.8",
     "copy-webpack-plugin": "^12.0",
     "css-loader": "^5.2",