Make the default playbook name "default.yml", and add error message for how to use this with a role or with `provisioner: playbook:` variable setting
Merge pull request #14 from trinitronx/trinitronx/make-default-playbook-more-obvious

Make the default playbook name "default.yml", and add error message for how to use this with a role or with `provisioner: playbook:` variable setting