Run all tasks on localhost without sudo

Playbooks are written to be run with '-s' or --sudo set so that
most tasks need not specify sudo: yes. This inadvertently forces
sudo (nopasswd) to  on development machine/localhost (making it
insecure) unless tasks run on localhost explicitly sets
  sudo: no

Change-Id: Ia20ac2f89dc1b02fb1286b71ac7959b31e8d28c2
removes unused compute_nodes.yml file

Change-Id: I82d63601a84367f5cbb23432b1255757ed724520