Updated environment setup

* moved site.pp to manifests/site.pp
 * created hiera.yaml file
 * created hieradata/nodes directory, included in hiera.yaml

environment.conf

@@ -1,2 +1,2 @@
-manifest = site.pp
+manifest = manifests/site.pp
 modulepath = external_modules:site

hiera.yaml

@@ -0,0 +1,8 @@
+---
+version: 5
+defaults:
+  datadir: "hieradata"
+  data_hash: "yaml_data"
+hierarchy:
+  - path: "nodes/%{trusted.certname}.yaml"    # Node-specific data, overrides other levels.
+  - path: "common.yaml"                       # Common data shared across nodes.