Bump node-sass from 4.13.1 to 7.0.0

Bumps [node-sass](https://github.com/sass/node-sass) from 4.13.1 to 7.0.0.
- [Release notes](https://github.com/sass/node-sass/releases)
- [Changelog](https://github.com/sass/node-sass/blob/master/CHANGELOG.md)
- [Commits](https://github.com/sass/node-sass/compare/v4.13.1...v7.0.0)

---
updated-dependencies:
- dependency-name: node-sass
  dependency-type: direct:development
...

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

package.json

@@ -108,7 +108,7 @@
     "jest": "24.9.0",
     "jest-cli": "24.9.0",
     "mini-css-extract-plugin": "0.9.0",
-    "node-sass": "^4.13.1",
+    "node-sass": "^7.0.0",
     "postcss-increase-specificity": "0.6.0",
     "postcss-loader": "3.0.0",
     "sass-loader": "8.0.0",