Initial implementation of HEAT CFN client and Template registration

This patch adds support for connecting to Heat using:

from tuskar.heat.client import HeatClient as heat_client

heat_client().method

Also update the #index action in DataCenter controller to support
template validation and registration.
Added 'boto' to list of requirements
Merge pull request #36 from mfojtik/heat

Initial implementation of HEAT CFN client and Template registration