chore(deps-dev): bump grunt-sass from 3.0.2 to 3.1.0 (#12)

Bumps [grunt-sass](https://github.com/sindresorhus/grunt-sass) from 3.0.2 to 3.1.0.
- [Release notes](https://github.com/sindresorhus/grunt-sass/releases)
- [Commits](sindresorhus/grunt-sass@v3.0.2...v3.1.0)

Signed-off-by: dependabot[bot] <[email protected]>

Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>