Create a very simple end-to-end example to run a QA workflow

[agstephens]

Proposed plan...

Input data:

• Collection: https://api.stac.ceda.ac.uk/eo/collections/Sentinel-2A
• Item: https://api.stac.ceda.ac.uk/eo/collections/Sentinel-2A/items/6d010854a589dd5980442d7947be6233574ab442

Simple python code as the QA checker:

• N functions that check the STAC content
• function names should indicate what the check does

Output:

• 1 JSON file containing anything relevant:
  • per-metric results (including details, links etc)
  • general metadata about the specification, etc.:
  • probably with dead links to future documents/sites
  • author, date created, version and description of software environment

[shunt16]

Minimal QA check prototype now in 3-example_workflow branch

[shunt16]

Extend to include:

• Run multiple tests in single process?
• Handling of logging
• Interaction with event and notification service
• Control vocabulary?
• unittest
• yaml for tests per collection
• some kind of container of checks