Add py-testrepository 0.0.20

The package provides a database of test results which can be used as part of
developer workflow to ensure/check things like:

• No commits without having had a test failure, test fixed cycle.
• No commits without new tests being added.
• What tests have failed since the last commit (to run just a subset).
• What tests are currently failing and need work.

Test results are inserted using subunit (and thus anything that can output
subunit or be converted into a subunit stream can be accepted).

WWW: https://launchpad.net/testrepository

PR: 228692
Submitted by: Kai <freebsd_ports@k-worx.org>