Allow users to expire, keep, or disable storage of job information

[paul-finary]

Currently, the information attached to a job that has been processed are necessarily stored back in redis. In some cases, this is not needed, and unwanted.

I added a way for users to disable this feature by making the ttl have three states:

• positive (e.g. 600): the job is saved back to redis with an expiry after processing
• neutral (e.g. 0): the job is saved back to redis without expiry
• negative (e.g. -1): the job is not saved back to redis

I thought about using positive, None, and 0, but decided to stay with one type, not sure what's best honestly.

[paul-finary]

I dig -1.

Can you add a test for this?

Just added several tests for the 3 different ttl "states"