Abstract node definitions out of vagrant

This commit abstracts the node configurations out of
Vagrant so that they can be defined seperately as configuration.
Merge pull request #44 from bodepd/abstract_nodes

Abstract nodes
Update puppet-db package base_url

The base_url for the puppet-db package wasn't parameterized. it is now
Merge pull request #45 from robertstarmer/puppetfile_fix_baseurl

Update puppet-db package base_url