Add plugin to PROJECTS in keystone jobs
Add plugin to PROJECTS in keystone jobs

We forgot to add the keystone-tempest-plugin project to the PROJECTS
list so the keystone v3 nonvoting jobs are failing with "Invalid
requirement: '/opt/stack/new/keystone-tempest-plugin'".

Change-Id: I727866d4aa8ad3ef8962752dacce3a0e37d1ac01

openstack-infra/project-config,openstack-infra/project-config