Switch to Hiera 5

[smortex]

This avoids a bunch of warnings when the Puppet Master use the module:

Warning: /usr/local/etc/puppet/environments/production/modules/bacula/hiera.yaml: Use of 'hiera.yaml' version 4 is deprecated. It should be converted to version 5
   (file: /usr/local/etc/puppet/environments/production/modules/bacula/hiera.yaml)
Warning: Defining "data_provider": "hiera" in metadata.json is deprecated.
   (file: /usr/local/etc/puppet/environments/production/modules/bacula/metadata.json)

While here, single-quote all strings in hiera.yaml for consistency and
add blanks in a similar fashion to the puppetlabs-ntp module.

[zachfi]

Thank you @smortex.