Nightly jobs come back green even if they have test failures

[mikaelarguedas]

I noticed this in the last nightlies but it seems that's been happening for a while:
https://ci.ros2.org/view/nightly/job/nightly_linux_debug/846/consoleFull#console-section-518

Summary: 17110 tests, 0 errors, 5 failures, 19 skipped but the job is green

Looks like the linux jobs started failing on https://ci.ros2.org/view/nightly/job/nightly_linux_debug/838/

[dhood]

maybe just the "pure" pytest failures don't get picked up

[dirk-thomas]

All "missed" test results are of the form build/<pkgname>/pytest.xml. The configured paths for the Jenkins plugin extracting the warnings simply don't match these paths.

[dirk-thomas]

Some of the test failures have been addressed by the referenced PRs. The remaining ones are due to a regression in the latest Pyflakes release 2.0.0 (see PyCQA/pyflakes#333). Hopefully upstream will be able to resolve this quickly and we don't have to add noqa ignores to these lines.