Bump bootstrap from 4.0.0 to 4.3.1 in /works

Bumps [bootstrap](https://github.com/twbs/bootstrap) from 4.0.0 to 4.3.1.
- [Release notes](https://github.com/twbs/bootstrap/releases)
- [Commits](twbs/bootstrap@v4.0.0...v4.3.1)

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

Author: dependabot[bot]