The Infra Cloud project uses a different set of puppet modules than the
standard infra ones in order to avoid possible dependency conflicts[1].
Currently the puppet-apply test hard-codes the entry-point puppet
manifest and module list. This patch makes the manifest, currently
manifests/site.pp, and the module file, currently modules.env,
configurable, so that we can add a new job to test just these nodes
with the correct modules installed.
[1] https://review.openstack.org/#/c/209617/
Change-Id: I744123befef0bf27a1eb2a79f5d814e0cefe81f5