Like the 'puppet-masterless' and 'puppet-server' provisioners (and
unlike the 'chef-solo' and 'chef-client' provisioners), the
'ansible-local' currently requires Ansible to be present on the
provisioned image.
The relevant issue to add an install option to the provisioner is:
https://github.com/mitchellh/packer/issues/2010
Until then, a notice similar to the 'puppet-masterless' and
'puppet-server' ones is added.