Maintenance: Bump guard from 2.17.0 to 2.18.0
Maintenance: Bump guard from 2.17.0 to 2.18.0

Bumps [guard](https://github.com/guard/guard) from 2.17.0 to 2.18.0.
- [Release notes](https://github.com/guard/guard/releases)
- [Commits](https://github.com/guard/guard/compare/v2.17.0...v2.18.0)
monotek/zammad,zammad/zammad,zammad/zammad,monotek/zammad,zammad/zammad,zammad/zammad,zammad/zammad,zammad/zammad,monotek/zammad,monotek/zammad,monotek/zammad,monotek/zammad