Update responders requirement from ~> 2.0 to >= 2, < 4
Update responders requirement from ~> 2.0 to >= 2, < 4

Updates the requirements on [responders](https://github.com/plataformatec/responders) to permit the latest version.
- [Release notes](https://github.com/plataformatec/responders/releases)
- [Changelog](https://github.com/plataformatec/responders/blob/master/CHANGELOG.md)
- [Commits](https://github.com/plataformatec/responders/compare/v2.0.0...v3.0.0)

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