Bump mini-css-extract-plugin from 1.2.1 to 1.3.0

Bumps [mini-css-extract-plugin](https://github.com/webpack-contrib/mini-css-extract-plugin) from 1.2.1 to 1.3.0.
- [Release notes](https://github.com/webpack-contrib/mini-css-extract-plugin/releases)
- [Changelog](https://github.com/webpack-contrib/mini-css-extract-plugin/blob/master/CHANGELOG.md)
- [Commits](webpack-contrib/mini-css-extract-plugin@v1.2.1...v1.3.0)

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

Author: dependabot[bot]

package.json

@@ -21,7 +21,7 @@
     "clean-webpack-plugin": "3.0.0",
     "cross-env": "7.0.2",
     "css-loader": "5.0.1",
-    "mini-css-extract-plugin": "1.2.1",
+    "mini-css-extract-plugin": "1.3.0",
     "postcss-loader": "3.0.0",
     "sass": "1.29.0",
     "sass-loader": "10.0.5",