Sentinel and server at parallele

[jorijinnall]

Hello,

I would be good to be able to run a redis-server instance on default port (6379) and sentinel instance at the same time. I propose a modification of the role to handle this capacity.

[eRadical]

I've already done the same thing in our code base. Would love to see it merged.

[DavidWittman]

My only concern with this is that it changes behavior for users that relied only on the redis_sentinel flag, but I don't think that's too big of a deal. I'll get this merged after I confirm the test-kitchen runs still work and the documentation is updated.

[nogweii]

At my workplace we're also running the same configuration -- we have a number of dev redis clusters that run sentinel and redis on the same VM. This patch applies cleanly and works well.

[smutel]

Hello. Any update on this PR ? It would be good to have it ...