Update gc_ruboconfig requirement from ~> 2.12.0 to ~> 2.16.0
Update gc_ruboconfig requirement from ~> 2.12.0 to ~> 2.16.0

Updates the requirements on [gc_ruboconfig](https://github.com/gocardless/ruboconfig) to permit the latest version.
- [Release notes](https://github.com/gocardless/ruboconfig/releases)
- [Changelog](https://github.com/gocardless/gc_ruboconfig/blob/master/CHANGELOG.md)
- [Commits](https://github.com/gocardless/ruboconfig/commits)

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