Adapt kubespray to stack oriented framework

This change adapts installer kubespray to stack oriented framework
approach. The changes in summary are

- role package is moved to stack kubernetes
- apps and scenarios are moved from swconfig repo to this repo
- playbooks and roles pre-deployment and post-deployment are renamed to
  preinstall and postinstall respectively
- vars moved to kubernetes repository and only the installer version is
  controlled in this repo
- shellcheck outcome is ignored as the failures are due to moving
  scenarios and apps from swconfig repo and it will be enabled back once
  the issues are fixed

Change-Id: I36860547b6493c579b600c063ecb413151c370b7
73 files changed