Update bootstrap requirement from ~> 4.3.1 to >= 4.3.1, < 4.6.0
Update bootstrap requirement from ~> 4.3.1 to >= 4.3.1, < 4.6.0

Updates the requirements on [bootstrap](https://github.com/twbs/bootstrap-rubygem) to permit the latest version.
- [Release notes](https://github.com/twbs/bootstrap-rubygem/releases)
- [Changelog](https://github.com/twbs/bootstrap-rubygem/blob/master/CHANGELOG.md)
- [Commits](https://github.com/twbs/bootstrap-rubygem/compare/v4.3.1...v4.5.0)

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