There are still a few tests that rely on physical certificate files.
These are slightly more complicated to replace with pytest fixtures.
Updated the script for generating a CRL chain so that the CRL is good
for roughly ten years and regenerated the certs and CRL.
Adjust the broken tests to use our dynamic fixtures for PKI files. Some
tests still rely on these fixtures, but this is a minimal patch to get
the test suite passing again. Eventually all tests should use the pytest
fixtures.
