[DOC] stable/newton branch doesn't exist yet

[Nish Patwa]

In "checkout the newton release" section,first line says to checkout from the newton stable
release. But the stable branch for newton does not even exists in the repo.

I am getting the following error,once I hit the following command
error: pathspec 'stable/newton' did not match any file(s) known to git.

Should it be 'git checkout master' instead of 'git checkout stable/newton' ?

-----------------------------------
Release: 14.0.0.0b3.dev204 on 2016-08-25 20:12
SHA: 0f353207fb0a5f4446b5d4cc77a2570d626370ac
Source: http://git.openstack.org/cgit/openstack/openstack-ansible/tree/doc/source/upgrade-guide/manual-upgrade.rst
URL: http://docs.openstack.org/developer/openstack-ansible/upgrade-guide/manual-upgrade.html

[Jean-Philippe Evrard (jean-philippe-evrard)]

See the conversation here:
http://eavesdrop.openstack.org/irclogs/%23openstack-ansible/%23openstack-ansible.2016-08-30.log.html#t2016-08-30T16:28:48