Add information that redis-sentinel should not be used with redis >= 3.2

[Draiken]

We've had some problems after upgrading the redis gem while still using the redis-sentinel. It broke the newly added sentinel support on redis-rb 3.2 and didn't raise any errors. We only found out when deploying to production and the redis client was incorrectly attempting to connect to the localhost.

I'd love to see a warning on the readme or something, so this can be avoided by others in the future :)

[phallstrom]

👍

@Draiken - You find a solution?

[Draiken]

Yes, just removed the redis-sentinel gem, since the redis gem now supports it nativelly. Small change to the initial configuration, changing master_name: lala to url: redis://master.

[phallstrom]

Ah. And if I'd bothered to read more I would have seen this:

https://github.com/redis/redis-rb#sentinel-support

Definitely worth mentioning in this README/wiki somewhere I agree.