Bump scss-tokenizer and node-sass in /app

Bumps [scss-tokenizer](https://github.com/sasstools/scss-tokenizer) to 0.4.3 and updates ancestor dependency [node-sass](https://github.com/sass/node-sass). These dependencies need to be updated together.


Updates `scss-tokenizer` from 0.2.3 to 0.4.3
- [Release notes](https://github.com/sasstools/scss-tokenizer/releases)
- [Commits](sasstools/scss-tokenizer@v0.2.3...v0.4.3)

Updates `node-sass` from 4.14.1 to 8.0.0
- [Release notes](https://github.com/sass/node-sass/releases)
- [Changelog](https://github.com/sass/node-sass/blob/master/CHANGELOG.md)
- [Commits](sass/node-sass@v4.14.1...v8.0.0)

---
updated-dependencies:
- dependency-name: scss-tokenizer
  dependency-type: indirect
- dependency-name: node-sass
  dependency-type: direct:development
...

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