Add Redis Streams support in Transport Layer

[souvikhaldar]

What would you like?

I would like to add support for Redis Streams in the Transport Layer for supporting async communications.

[sagikazarmark]

As someone pointed out on the Slack channel, Go kit no longer accepts new transports in the core (at least for now). The reason being that with generics on the horizon it will undergo some changes and restructuring, most probably moving some of the packages out to separate repositories. (See more in #843)

The other reason is the realization that transports can live outside of the core and can be linked from the README so others can find it.