Specify which workflow tests we need

[vteague]

Examples:

• Make a simple workflow where we introduce a discrepancy into a not-covered CVR, then remove the discrepancy. Check that it goes back to zero, or understand why not.

(Note that 'isCovering' means 'was selected in the audit', not 'is present in the CVR' and that the ballot may have been selected for a different audit, so the contest may be present, but 'isCovering()' false.)