Bump node-sass from 4.9.2 to 4.13.1

Bumps [node-sass](https://github.com/sass/node-sass) from 4.9.2 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](sass/node-sass@v4.9.2...v4.13.1)

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

Author: dependabot[bot]

package.json

@@ -170,7 +170,7 @@
     "lint-staged": "^7.2.0",
     "mini-css-extract-plugin": "^0.4.1",
     "minimist": "^1.2.0",
-    "node-sass": "^4.9.2",
+    "node-sass": "^4.13.1",
     "npm-logical-tree": "^1.2.1",
     "optimize-css-assets-webpack-plugin": "^5.0.0",
     "prettier": "^1.14.0",