Create new repo to host legacy heat-cfn client.

Our cfn compatible clients (heat-cfn, heat-boto, heat-watch)
need to be moved out of the main heat server repo.

These tools are only useful to heat developers to debug
the CloudFormation compatible API, so openstack-dev has
been chosen as the most appropriate home.

There is no intention to do any pypi released from this
repo, and we will be instructing distro packagers to not
package these scripts.

Change-Id: I5a1f8cb51f20733fa9b91ebbd60fe3066e3313f8
Merge "Create new repo to host legacy heat-cfn client."