Update Parfait Release process to support latest PCP/containers

[tallpsmith]

The original Parfait release process I used relied on a Docker setup that worked because installing the older PCP in a container didn't try to start PCP at the end (or at least didn't error when it did so).

Some recent updates/upgrades to Parfait now also do not work well inside the container due to Mockito changes.

This issue addresses this so that we can complete a Parfait release (or at least I can on my Mac...)