Simplify FC passthrough setup

No longer have create-passthrough-private-key in the private repo.
Instead, create the file, and use e.g. git clone <repo> to pull it into
the node. This is simpler.
Don't use openstack pypi mirror.

Openstack pypi mirror is no longer being maintained.
Add in 'my' pypi mirror. Use this as a template to include
in your own private scripts. In the future, this could be made
configurable via template.