The previous heat-api is, in fact, a CloudFormation-compatible API. Rename
it to heat-api-cfn, analogous to how the EC2 API in Nova is named
nova-api-ec2.
Change-Id: I9759f10cee6a60cdc9cb917966eb9fb95a618f85
Signed-off-by: Zane Bitter <zbitter@redhat.com>