First stab at recipe-based configuration.

Cassandra is in.
Include the recipe to only have to say recipe[datadog::cassandra]
Updated the version number
Update README.md
Taking another, simpler approach.

Using a resource & provider to configure a source to monitor.
Work in progress
Merge branch 'master' into integration-recipes
Merge branch 'integration-recipes' of github.com:DataDog/chef-datadog into integration-recipes
Removed specific version for chef-handler that caused failure
Added mysql, replace ambiguous monitor name with ddmonitor
Postgres passes.

Now it's a matter of applying the same logic to the rest of
the integrations.
More integrations converted to the new style
Merge branch 'master' into integration-recipes
Added changes from Kiall's template work
Removed specific version requirement of chef_handler that was breaking
Added passwords.rb (temporary)
More changes to templates
fixed typo in recipes/couchdb.rb
typo in templates/default/rabbitmq.yaml.erb fixed, may still be incomplete..
Merge branch 'integration-recipes-new' of github.com:moniker-dns/chef-datadog into integration-recipes-new