First pass to adding analytics tiers in ec-metal

WIP: Not ready to merge yet

To do:

1) test tiered, standalone config in ec-metal.
2) modify the examples as per config assumptions for analytics

The `node['harness']` attributes won't be available inside the private-chef cookbook.    you'll need to pass the attributes down to the machines (see `ec-harness/providers/private_chef_ha.rb` )