Credits system for cost of 1

[jtherrmann]

Before merging to develop:

• implement dynamo.user.create_user()
• implement dynamo.user.decrement_credits()
• change return value of handlers.get_user() to match new openapi spec
• update user schema in openapi spec to replace quota with credits
• update job schema in openapi spec to include cost
• make sure priority starts at 9,999
• save important Users table records, then delete all records and re-create the important ones after merging
• fix failing tests
• add/update tests to reflect new requirements and perform manual test coverage review
• generate test coverage report to see if we missed adding/updating tests?
• TODO items in code
• Run a git grep -i for terms such as "quota" and "month" and either rename them or leave TODOs where the business logic needs to change; initial implementation should have no concept of monthly credit allotment
• Option to reset users' credits to 10,000 each month
• Address certain race conditions

[jtherrmann]

I reviewed all of the functions that we've added/changed/deleted as part of the credits system implementation and confirmed that test coverage is sufficient for added/changed functions and references to deleted functions have been removed:

apps/api/src/hyp3_api/handlers.py

• changed: post_jobs
• changed: get_user

lib/dynamo/dynamo/jobs.py

• deleted: _get_job_count_for_month
• added: _get_credit_cost (not tested directly)
• deleted: get_quota_status
• changed: put_jobs
• deleted: _get_job_priority
• added: _prepare_job_for_database (not tested directly)
• deleted: count_jobs

lib/dynamo/dynamo/user.py

• deleted: get_user
• deleted: get_priority
• added: get_or_create_user
• deleted: get_max_jobs_per_month
• added: _get_current_month (mocked, not tested)
• added: _create_user
• added: _reset_credits_if_needed
• added: decrement_credits

[jtherrmann]

Closing this issue and tracking remaining TODOs at #2055