Bump node-sass from 4.12.0 to 4.13.0

Bumps [node-sass](https://github.com/sass/node-sass) from 4.12.0 to 4.13.0.
- [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/v4.12.0...v4.13.0)

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

package.json

@@ -46,7 +46,7 @@
     "koa-views": "^6.1.4",
     "kue": "^0.11.6",
     "mini-css-extract-plugin": "^0.7.0",
-    "node-sass": "^4.11.0",
+    "node-sass": "^4.13.0",
     "nodebrainz": "^2.1.1",
     "pg": "^7.17.1",
     "playmusic": "^2.3.0",