Set Redis directory programatically

[dcorney]

The Redis config file specifies the directory to store the database in. Switching between different Redis stores would be nice, so we could (e.g.) have a novel-markov-chain and a news-markov-chain and a shakespearean-markov-chain etc.

[dcorney]

To programatically update the database of the directory, something like this:
sed -ie 's/^dir .*$/dir new-dir/g' redis.conf
I.e. search for a line starting 'dir' and replace it with a new directory line

Default value:
grep '^dir .*$' redis.conf

dir /usr/local/var/db/redis/
And can start redis by passing in config 'file' on stdin.
May need to mkdir first, or ensure it exists

[dcorney]

New fn. in redis_store.py to set new config name which contains new Redis directory.
BUT: this must be called before starting Redis, which must happen before started textgen itself.
So it should probably be moved to a separate module with its own CLI...