Re #8578 - Remaked tests files- created tests for new functions - set_certificate_revoked, clear_certificate_revocation, get_all_revoked_by, get_all_issued_by
Re #8476 - Changed structure of tests- Renamed DAO integration tests so that they are found by pytest- Moved RestAPI tests from UnitTests to IntegrationTests
Re #8472 - Improved SQL connection/cursor fixtures in such way that connection to DB happens only once per test module