Bumps [rubocop-ast](https://github.com/rubocop-hq/rubocop-ast) from 1.7.0 to 1.8.0.
- [Release notes](https://github.com/rubocop-hq/rubocop-ast/releases)
- [Changelog](https://github.com/rubocop/rubocop-ast/blob/master/CHANGELOG.md)
- [Commits](https://github.com/rubocop-hq/rubocop-ast/compare/v1.7.0...v1.8.0

)

---
updated-dependencies:
- dependency-name: rubocop-ast
  dependency-type: direct:production
  update-type: version-update:semver-minor
...

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