Remove unused file
Remove unused file

site.pp.downstream isn't referenced any longer in
puppet_openstack_builder code and is old compared to released
versions of COI Grizzly.  Since it's no longer used, it should
be removed.

Change-Id: I796fa8376f3e6a76ae6a11dcb80730b38df81818

michaeltchapman/puppet_openstack_builder,michaeltchapman/vagrant-consul,phchoic/puppet_openstack_builder,CiscoSystems/puppet_openstack_builder,phchoic/puppet_openstack_builder,CiscoSystems/puppet_openstack_builder,michaeltchapman/puppet_openstack_builder,phchoic/puppet_openstack_builder,michaeltchapman/puppet_openstack_builder,michaeltchapman/vagrant-consul