Remove TestConvertHessBook and TestDebugHess (both referenced a
non-existent Hess EPUB at an absolute local path) and
TestConvertCPByTextSearch (referenced a Crime and Punishment EPUB
in the local uploads directory). These were development-time debug
tests that only worked on the author's machine.
All CFI/KEPUB conversion behavior is already covered by the proper
fixture-based tests (TestKEPUBRoundTrip, TestKEPUBConvertKEPUBToStandard,
TestKEPUBConvertWithEmElements, etc.) which use createTestEPUB and
createTestKEPUB helpers.