Make upgrade working outside functionnal tests

- Avoid the cloning of SF by ansible as the ansible
playbook is provided in the cloned repo. So manage that
externaly.
- Substitute TO, FROM, and DOMAIN in group_vars/all
according to role_configrc and sfconfig.yaml.
- Remove the backup task as credentials only known
by the user is needed.

Change-Id: Ia3177b7c641a84f0199a5a74422bcaeee9d32378