Consider using sql alchemy instead of psycopg as core sql library

[matthewgee]

Do we want to preserve the ability for abacus users to easily be able to use the library with a non-PostgreSQL data store or even structured CSVs?

Essentially separate our the connection and query methods from the calculations. I can be convinced otherwise.

[tplagge]

Connection/query and calculation methods are already separated, but the connection/query routines (in input_db) do assume Postgres. This would be a relatively painless change if we wanted to support non-Postgres databases, and in fact I'm about 100% certain we'll need to do this for queries to the wage records database. Fairly low priority at the moment, but this is a good change to keep on our radar.

[NdagiStanley]

Just came across this as an open issue. Does it make sense to close this issue and mark the repo as archived since I'm not seeing recent activity in it?

cc @matthewgee