Support for Rails 6

[genreil]

Hi,

Are you planning to support Rails 6? If so, could you please make the adjustments.

Thanks a lot!

[tubedude]

Supported as of v1.0.0, which depends on activesupport >= 6.1, < 8 — so Rails 6.1 and Rails 7 both work (tested against activesupport 7.2). (#36)