Bump css-loader from 2.1.0 to 3.0.0 (#2021)

Bumps [css-loader](https://github.com/webpack-contrib/css-loader) from 2.1.0 to 3.0.0.
- [Release notes](https://github.com/webpack-contrib/css-loader/releases)
- [Changelog](https://github.com/webpack-contrib/css-loader/blob/master/CHANGELOG.md)
- [Commits](https://github.com/webpack-contrib/css-loader/compare/v2.1.0...v3.0.0)

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

package.json

@@ -33,7 +33,7 @@
     "browserslist": "^4.4.1",
     "caniuse-lite": "^1.0.30000938",
     "codecov": "^3.2.0",
-    "css-loader": "^2.1.0",
+    "css-loader": "^3.0.0",
     "cssnano": "^4.1.10",
     "eslint": "^5.14.1",
     "eslint-plugin-flowtype": "^3.4.2",