Implement OS::Sahara::NodeGroupTemplate resource

Change-Id: I3f212f960bce360a26f52d56121ef35c9762abbe
Implements: blueprint sahara-as-heat-resource
Implement OS::Sahara::ClusterTemplate resource

Change-Id: I19ffbc19340342f716aa0c23e2b9dd4332503cdc
Implements: blueprint sahara-as-heat-resource
Merge "Implement OS::Sahara::NodeGroupTemplate resource"
Merge "Implement OS::Sahara::ClusterTemplate resource"