Add Redis version 4 support

[xdzurman]

Hello!

The lib works great with Redis version 3.1.2, but 3 months ago, version 4 has been released and does not work. I debugged a little bit and it seems that the current redis calls hgetall, hset, ..., are camelCased in version 4 and do not work here anymore. Could this please be updated?

Great work btw.

[sunlee-newyork]

second this!

[ghinks]

would any of you folks be interested in a collaboration to get version 4 working?

[rqroz]

@ghinks hit me up I'd be interest in collaborating.

[ghinks]

Just leaving work and will take a look at it.

[ghinks]

I would be glad to collaborate @rqroz. I have a concern. There has not been much activity recently and is @kwhitley good with us making this PR. It will have to be merged and I am not sure how active this repo is ?