Issue 281 v5 sadd srem return value

[CoderMiguel]

attempting to fix https://github.com/sds/mock_redis/issues/281

[sds]

Hey @CoderMiguel, thanks for your effort on this.

As mentioned in this comment, very supportive of dropping support for redis-rb < 5 if it makes it easier for us to move forward here. Looking at the changelog going from 4 → 5, it seems pretty trivial to migrate, and 5.0.0 was released over 1.5 years ago. Would absolutely be in favor of requiring 5.0+ and removing any code specific to 4.x. Thanks!

If you rebase this PR on top of the latest main branch, the CI linting should be fixed now.

[CoderMiguel]

@sds this should be rebased now, I will revisit soon to look into the test failures and remove the version checking code I added for testing some things out.