Redis INFO redis_version

[portertech]

Perhaps INFO "redis_version" should be the redis version this lib is inline with, for applications that use this to verify the running version meets requirements.

Current:

-> % redis-cli
redis 127.0.0.1:6379> info
redis_version:0.0.2
redis_git_sha1:Ruby
redis_git_dirty:1

[AE9RB]

I'm not sure what is best here. I can't imagine anyone using the naked Ruby server without modification. Once modified, it's not tracking the C Redis feature set any more.