TODO

add ecto starter bits
add poll worker
persist from a single poll
determine/add scheduling of polls
- Could use a cron-like string stored on the procedure
  - con: Would potentially be a pain to find (or have to implement) parsing the cron string
  - Then just do Process.send_at, or a state_timeout (if using gen_statem)
- Could use db records of scheduled times
  - pro: scheduling code is simpler
  - con: more load and dependence on the db
  - con: less obvious what the "schedule" is for a given procedure
- Could investigate Oban (never used) or Quantum (seen implemented poorly)
add external_payor_id to payor_procedures
add procedure_endpoint field to payors
- for use with PayorClient (also tbd)

Nice to haves

ability to load/reload procedures to poll w/o restarting the app
supervision strategies that don't restart the world, or cause a thundering herd
pooling for poll workers
- determine how we want to pool (potentially by payor in case their APIs suck, but that adds constraints to the scheduling of all payors)
swap default timestamps() to be utc_datetime_usec

dropping the payors table and using an enum instead
- originally what I was considering doing before I started making tables
- has the negative that postgres makes it difficult to drop enum values
change reimbursement_amounts to join to a new table reimbursement_intervals
- reimbursement_amounts.replaced_at goes away
- con: if only one amount is updated it just moves a duplicated-"amount"-record problem into a new join table
- probably needs more clarification on why "intervals" are necessary (didn't have time :-/ )