* Fix bug with test for securityChecks option which caused it to be skipped.
* Convert tests to JSON output only, and update them for Trivy 0.28.1.
* Update CI test to use Trivy 0.28.1.
* Add support for supplying one or more .trivyignore files.
* Fix gitignore for test data.
* Add test for trivyignores option.
* Be explicit about the trivy options we use during testing.
* Add documentation of trivyignores option.