Bump node-sass from 4.7.2 to 7.0.0

Bumps [node-sass](https://github.com/sass/node-sass) from 4.7.2 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](sass/node-sass@v4.7.2...v7.0.0)

---
updated-dependencies:
- dependency-name: node-sass
  dependency-type: direct:production
...

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

Author: dependabot[bot]

package.json

@@ -125,7 +125,7 @@
     "moment": "^2.18.1",
     "moment-timezone": "^0.5.13",
     "nconf": "^0.8.1",
-    "node-sass": "^4.0.0",
+    "node-sass": "^7.0.0",
     "nodemon": "^1.8.1",
     "postcss-loader": "^0.13.0",
     "prop-types": "^15.5.10",