Job fingerprinting

[kevinkle]

This will likely be done with to move to a custom Job class. The idea would be to:

1. fingerprint (read: hash) the job submission
2. lookup this hash in blazegraph
3. a. If found, rebuild the results from the graph
4. b. If not, run the job and tag the hash onto the results.

[kevinkle]

This is effectively the solution to #204 . But will keep both open in case this approach doesn't work as intended.

[kevinkle]

Fingerprints in https://github.com/superphy/spfy/releases/tag/v6.2.0 are deterministic. We're going to do it as described above, but also use redis as an buffer.