Bump node-sass from 4.14.1 to 7.0.0

Bumps [node-sass](https://github.com/sass/node-sass) from 4.14.1 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](sass/node-sass@v4.14.1...v7.0.0)

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

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

package.json

@@ -35,7 +35,7 @@
     "eslint": "^6.7.2",
     "eslint-plugin-prettier": "^3.1.1",
     "eslint-plugin-vue": "^6.2.2",
-    "node-sass": "4",
+    "node-sass": "7",
     "prettier": "^1.19.1",
     "sass-loader": "^8.0.2",
     "vue-template-compiler": "^2.6.11"