Create harvest source preprocess function in harvest.py

[rshewitt]

User Story

In order to process a harvest source, the harvest runner needs a function to fetch harvest source information from the harvest database via a job id

Acceptance Criteria

[ACs should be clearly demoable/verifiable whenever possible. Try specifying them using BDD.]

• [ ] GIVEN harvest.py
  WHEN the HarvestSource is instantiated
  THEN harvest source information will be fetched and assigned as attributes to the instance \

Background

• the harvest runner is only being provided a job id of what to process
• the runner will need to fetch the necessary harvest source information in order to process the harvest source ( e.g. url, type, organization, etc...)

Security Considerations (required)

[Any security concerns that might be implicated in the change. "None" is OK, just be explicit here!]

Sketch

• refactor HarvestSource class to only require the job_id
  • refactor all HarvestSource instantiations in the repo
• create preprocess function to read harvest source record
• implement inside post_init function
• create new class inheriting from the critical exception class and raise it appropriately during preprocess

[rshewitt]

updated part of the sketch. this ticket involves refactoring the HarvestSource class and all tests referencing it so some additional time will be needed.