Update less-loader requirement in /{{cookiecutter.app_name}} (#469)

Updates the requirements on [less-loader](https://github.com/webpack-contrib/less-loader) to permit the latest version.
- [Release notes](https://github.com/webpack-contrib/less-loader/releases)
- [Changelog](https://github.com/webpack-contrib/less-loader/blob/master/CHANGELOG.md)
- [Commits](https://github.com/webpack-contrib/less-loader/compare/v4.0.4...v5.0.0)

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

{{cookiecutter.app_name}}/package.json

@@ -40,7 +40,7 @@
     "file-loader": "^2.0.0",
     "font-awesome-webpack": "0.0.5-beta.2",
     "less": "^3.8.0",
-    "less-loader": "^4.0.4",
+    "less-loader": "^5.0.0",
     "manifest-revision-webpack-plugin": "^0.4.0",
     "raw-loader": "^0.5.1",
     "style-loader": "^0.23.0",