Refactor Load Manager into Class Inheritance Pattern for new CF Tasks Client

[btylerburton]

User Story

In order to support more operations using the CF Handler client, datagovteam wants to create a TaskManager client base class and then extend that to support the Load Manager.

Acceptance Criteria

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

• GIVEN I have created a base TaskManager class
  THEN I want to extend that class to support an instance of the Load Manager
  AND I want it to support all of the operations that that script currently supports

• GIVEN I want to perform some other operation using the CF Tasks Client
  THEN I want to extend the base TaskManager class by to perform that.

Background

CF Task Manager will ultimately be needed to invoke other batch operations such as harvest source deletion, and reporting back the state of all tasks on the datagov-harvest-runner.

Security Considerations (required)

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

Sketch

• Create base TaskManager class with general purpose interactions with the CF Handler
• Refactor LoadManager script into an inheritance class of TaskManager
• Ensure all current tests pass