Need add releasenote support in correct way

[ChangBo Guo(gcb)]

Some oslo libraries have supported release notes, but didn't do that in the right way. This lead we can't pass release validate. show errors like:

2016-10-18 01:41:03.732911 | Could not fetch release notes page http://docs.openstack.org/releasenotes/automaton/unreleased.html: 404
2016-10-18 01:41:03.732942 | Could not fetch release notes page http://docs.openstack.org/releasenotes/debtcollector/unreleased.html: 404
2016-10-18 01:41:03.732970 | Could not fetch release notes page http://docs.openstack.org/releasenotes/futurist/unreleased.html: 404
2016-10-18 01:41:03.732998 | Could not fetch release notes page http://docs.openstack.org/releasenotes/oslo.i18n/unreleased.html: 404
2016-10-18 01:41:03.733038 | Could not fetch release notes page http://docs.openstack.org/releasenotes/oslo.middleware/unreleased.html: 404
2016-10-18 01:41:03.733078 | Could not fetch release notes page http://docs.openstack.org/releasenotes/oslo.privsep/unreleased.html: 404
2016-10-18 01:41:03.733109 | Could not fetch release notes page http://docs.openstack.org/releasenotes/oslo.reports/unreleased.html: 404
2016-10-18 01:41:03.735503 | Could not fetch release notes page http://docs.openstack.org/releasenotes/oslo.rootwrap/unreleased.html: 404
2016-10-18 01:41:03.735549 | Could not fetch release notes page http://docs.openstack.org/releasenotes/oslo.serialization/unreleased.html: 404
2016-10-18 01:41:03.735578 | Could not fetch release notes page http://docs.openstack.org/releasenotes/oslo.service/unreleased.html: 404
2016-10-18 01:41:03.735606 | Could not fetch release notes page http://docs.openstack.org/releasenotes/oslo.utils/unreleased.html: 404
2016-10-18 01:41:03.735635 | Could not fetch release notes page http://docs.openstack.org/releasenotes/oslo.versionedobjects/unreleased.html: 404
2016-10-18 01:41:03.735674 | Could not fetch release notes page http://docs.openstack.org/releasenotes/oslosphinx/unreleased.html: 404
2016-10-18 01:41:03.735699 | Could not fetch release notes page http://docs.openstack.org/releasenotes/oslotest/unreleased.html: 404
2016-10-18 01:41:03.735724 | Could not fetch release notes page http://docs.openstack.org/releasenotes/stevedore/unreleased.html: 404
2016-10-18 01:41:03.735749 | Could not fetch release notes page http://docs.openstack.org/releasenotes/taskflow/unreleased.html: 404
2016-10-18 01:41:03.735773 | Could not fetch release notes page http://docs.openstack.org/releasenotes/tooz/unreleased.html: 404