Publish *-specs better

Do not include doc/build/html in the URL.

Thus, instead of publishing keystone-specs to:
http://specs.openstack.org/openstack/keystone-specs/doc/build/html/
publish instead to:
http://specs.openstack.org/openstack/keystone-specs/

Since the scp plugin does not allow removal of the path, we have to
copy the content up and publish from there.

Change-Id: I09f4654648f9da74f2e485d1c90082cfc835ab89