Simplified Redis connection creation

[tobiashm]

Redis-rb has a built in URL parser, which also handles specifying db # etc.

[lucasefe]

+1

(I removed the explanation because the reason is already on the commit message)

[inkel]

I'd really like to see this merged, though it'd probably be better to supply a Redis.new instance directly, so I can use a socket to connect to Redis if I wanted to.

[tobiashm]

@inkel you can use a unix socket with Redis given a URL like unix:///path/to/socket

[inkel]

Thanks @tobiashm, but what about if I want to indicate a differente Redis database number? Or to have authentication?

In fact, I would allow passing whatever arguments I like to Redis.new, but maybe it's just me :)

[tobiashm]

I think an alternative option to pass in a Redis instance would also be nice. But the purpose of this pull request is simply to improve the handling of redis_url.