Hobble controller

changes done by @twaldrop and myself while dropping dedicated controllers into an existing stack.

- crafted a hobble-controller playbook that removes all Network, Database, and controller services and packages.
- modify bootstrap_ml2 play book to target 'all' hosts (we needed to target these new controllers that do not have compute role)
- a fixup for the swap deletion code in ursula.  To get our runs to work we had to modify the implementation by moving the bash code into a script and then executing it.

I still think you could save a lot of time by putting all the apt packages you want to purge into a with_items list, and then call the apt module once. Ansible is smart enough to stick all of those into a single call.