The code is switching from relying on metadata based groups to
dynamically created groups with add_host.
As such, the group containing zuul is now 'zuul'.
Change-Id: Ia1336382b489f16a18ca00a67f985d41aad57319
Remove duplicated tasks line.
This is also reported when runnning: ansible-playbook --syntax-check.
Change-Id: Iad7b205418b57e6f38f2c4851ec2624a93689539