Move role deployment steps into puppet/post.yaml

Move role deployment steps into puppet/post.yaml

To enable steps to be aligned between roles, we need to define
dependencies between the steps, which is only possible if we
move the steps out of distinct nested stacks so we can use
depends_on to serialized the steps for all roles.

Note that we may be able to further refactor later to remove the
per-role -config.yaml nested stacks as well.

Change-Id: Ia2ea559e8eeb64763908f75705e3728ee90b5744
Partially-Implements: blueprint custom-roles