Add release notes job template
Add release notes job template

Without this job template there are no release notes published [1].

[1] https://docs.openstack.org/releasenotes/python-cloudkittyclient

Change-Id: I8ab231a4c563ecc2f8db22bade12bf4afa9fafc8

stackforge/python-cloudkittyclient,openstack/python-cloudkittyclient