The code is switching from relying on metadata based groups to
dynamically created groups with add_host.
As such, the group containing jenkins is now 'zuul'.
Change-Id: I5958a9fda04255daa028aaf779a208bd517d44a6
Remove duplicated tasks line.
This is also reported when runnning: ansible-playbook --syntax-check.
Change-Id: Iad7b205418b57e6f38f2c4851ec2624a93689539