Use hashes to store objects in Redis

[evanp]

We might want to store JSON objects as hashes rather than as strings.

http://redis.io/commands#hash

Then again, we don't really have an easy way to do anything smart with them, so unless we're planning on adding that at some point, it might not be worth it.

Originally from https://github.com/evanp/databank/issues/18