Bump node-sass from 3.13.1 to 4.14.1

Bumps [node-sass](https://github.com/sass/node-sass) from 3.13.1 to 4.14.1.
- [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/v3.13.1...v4.14.1)

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

package.json

@@ -37,7 +37,7 @@
     "grunt-retire": "~0.3.10",
     "grunt-zip": "~0.17.1",
     "mustache": "~2.2.1",
-    "node-sass": "~3.13.0",
+    "node-sass": "~4.14.1",
     "socket.io": "^1.4.8"
   },
   "license": "MIT"