Expand dat support

[aboutaaron]

This is a general ticket for integrating our data pipeline into maxogden/dat.

See #282 and #281 for other dat related tickets.

[palewire]

To simplify things, lets consolidate all of the dat tickets into this one with a more straightforward checklist of work to be done.

• [x] Determine how many models are missing unique keys
• [ ] Define unique keys defined for all data tables
• [ ] Develop a management command that verifies unique keys against the raw data (#1146)
• [ ] Develop a management command to guess any missing unique keys by querying the database (#1147)
• [ ] Upgrade our pydat wrapper and aim for Python 3 support (#282)
• [ ] Integrate dat into unittests (#281)
• [ ] Add dat usage and development guides to the documentation (#280)

[emilbayes]

So I gave @aboutaaron a few pointers on this at NICAR16, and you might want to watch what @karissa is doing with the publicbits/publicbits.org project. dat requires a local installation of Node.js and the dat cli. I don't know if publicbits.org will allow you to send your data straight there and get around having Node.js as a dependency of the project

[aboutaaron]

Dat has us featured on their site though data is a month old: https://datproject.org/view/79cf7ecc9baf627642099542b3714bbef51810da9f541eabb761029969d0161b

We should reach out to Karissa, Max and co. and ensure that they're pulling our latest data. I'll email 'em shortly.