Add python-novaclient and simpleyaml to requirements (for novaclient & config)
Nova client for flavors and nova config file (temp - yaml for now)
Updates controllers to use nova flavors client where appropriate (create/delete flavor
or ResourceClass with flavor). Adds nova_flavor_uuid to Flavor model for tracking
the nova created flavors
Merge pull request #45 from marios/nova_client

Nova client for Flavor model
Added python-heatclient back to requirements.txt
Refactored Heat API configuration

- All settings moved to tuskar.conf
Return the Heat stack in JSON on DataCenter#index