Hiera and Manifest

Previously, there was no Hiera data in this repository.  This commit
adds a base hiera.yaml and a site.pp.
Update datadir

Previously, the hiera.yaml file had no datadir by which to use to look
for hiera YAML files. This commit points it to look in each environment's
hieradata folder.
Remove Hiera data

Hiera data will be stored in a separate repository altogether, so
let's remove it shall we?