Bump node-sass from 4.12.0 to 4.13.1

Bumps [node-sass](https://github.com/sass/node-sass) from 4.12.0 to 4.13.1.
- [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...v4.13.1)

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

package.json

@@ -74,7 +74,7 @@
     "moment": "^2.24.0",
     "mz": "^2.7.0",
     "node-fetch": "^2.3.0",
-    "node-sass": "^4.11.0",
+    "node-sass": "^4.13.1",
     "node-uuid": "^1.4.8",
     "passwords": "^1.3.1",
     "pg": "^7.17.1",