add support for managing users that can ssh to a node via key

pillar/users/pillar.example

@@ -0,0 +1,19 @@
+users:
+  sclapton:
+    # required fields
+    status: present
+    # node_access determines which node types the user can access.
+    # this can either be by grains.role or by final part of the minion id after the _
+    node_access:
+      - standalone
+      - searchnode
+    # optional fields
+    - fullname: Stevie Claptoon
+    - uid: 1001
+    - gid: 1001
+    - homephone: does not have a phone
+    groups:
+      - mygroup1
+      - mygroup2
+      - wheel # give sudo access
+