Fixed a bunch of apex tests that assumed that statements in static blocks
would only run once per test, which no longer holds since @TestSetup methods
have been introduced.
Got nerd sniped by a request for book recommendations on building software from marmida.
May end up turning Salesforce to ShipCompliant integration into a product more-or-less, primarily to reduce up-front cost on custom integration, but perhaps other companies would find it useful.