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:production
...

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

package.json

@@ -30,7 +30,7 @@
     "hexo-server": "^1.0.0",
     "lodash": "^4.17.13",
     "lunr": "^2.3.8",
-    "node-sass": "4.13.1",
+    "node-sass": "7.0.0",
     "uuid": "^3.3.3"
   },
   "devDependencies": {