Add etc/designate/*.yaml to .gitignore
Add etc/designate/*.yaml to .gitignore

With recent changes to pool manager config, it is common for users to
have a pool.yaml in etc/designate.

Change-Id: I9c852139907c50c96d33eaa62fa6b006c1ff85e8

openstack/designate,openstack/designate,openstack/designate