There are two cases when we may want to delete things:
1. if a desired node configuration or spec changes, we delete existing node
resources.
2. if we use the teardown.yml playbook, cmd == teardown, delete
everything, including global state.
In both cases, Tenks state (state.yml), all nodes to be deleted are given a
'state' of absent'. We should therefore use this rather than the 'cmd' variable
which only works in the latter case.
Change-Id: Icc033340c7fd882e61d90e3d086f7ba4a5b673bf
Story: 2004907
Task: 29257
7ad354c2af