Without this change the "Import variables specific to distribution"
tasks fail with "Could not find file on the Ansible Controller..."
on environments with inject facts disabled.
This changes the tests to run with ansible with
inject_facts_as_vars = false and fixes other roles and playbooks.
This patch fixes handling of password and public_key files, parameter
validation depending on vault type, usage of `salt` attribute and data
retrieval.
Tests were updated to reflect the changes.
New example playbooks are added:
playbooks/vault/vault-is-present-with-password-file.yml
playbooks/vault/vault-is-present-with-public-key-file.yml
playbooks/vault/retrive-data-asymmetric-vault.yml
playbooks/vault/retrive-data-symmetric-vault.yml