The validation check is looking for a "publish-to-pypi-neutron-python3"
job to be set in the project-config repository for the neutron projects
but, that job doesn't seem to exist. This patch is changing the
validation script to look for a "publish-to-pypi-python3" job instead.
Change-Id: I9d2c6c82e78f798b12a8cadd633f6b247127133b