Add a puppet element.

Currently just installs the puppet package. This
will be a requirement for the puppet-modules package.

Change-Id: Iddf86e8ccb196b6c54288784384d9bb367523532

elements/puppet/README.md

@@ -0,0 +1,5 @@
+Installs the the Puppet package.
+
+Configuration
+-------------
+None.

elements/puppet/element-deps

@@ -0,0 +1 @@
+pkg-map

elements/puppet/install.d/74-puppet

@@ -0,0 +1,4 @@
+#!/bin/bash
+set -eux
+
+install-packages -m puppet puppet_package

elements/puppet/pkg-map

@@ -0,0 +1,5 @@
+{
+  "default": {
+    "puppet_package": "puppet"
+  }
+}