Update thor requirement from ~> 0.18 to >= 0.18, < 2.0
Update thor requirement from ~> 0.18 to >= 0.18, < 2.0

Updates the requirements on [thor](https://github.com/wycats/thor) to permit the latest version.
- [Release notes](https://github.com/wycats/thor/releases)
- [Changelog](https://github.com/erikhuda/thor/blob/master/CHANGELOG.md)
- [Commits](https://github.com/wycats/thor/compare/v0.18.0...v0.20.3)

Signed-off-by: dependabot-preview[bot] <5bdcd3c0d4d24ae3e71b3b452a024c6324c7e4bb@dependabot.com>
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