Prepare the deployment host in openstack-ansible

[Fabien Magagnosc]

- [X] This doc is inaccurate in this way: there is no branch 19.0.2, but instead OpenStack release name like stable/stein, or /stable/rocky ... See below a sample git clone execution

[root@deployer01 ~]# git clone -b 19.0.2 https://opendev.org/openstack/openstack-ansible /opt/openstack-ansible
Cloning into '/opt/openstack-ansible'...
fatal: Remote branch 19.0.2 not found in upstream origin
[root@deployer01 ~]# Unexpected end of command stream

[root@deployer01 ~]# git clone -b stable/stein https://opendev.org/openstack/openstack-ansible /opt/openstack-ansible
Cloning into '/opt/openstack-ansible'...
remote: Enumerating objects: 71235, done.
remote: Counting objects: 100% (71235/71235), done.
remote: Compressing objects: 100% (28353/28353), done.
remote: Total 71235 (delta 47961), reused 62390 (delta 39867)
Receiving objects: 100% (71235/71235), 17.75 MiB | 4.15 MiB/s, done.
Resolving deltas: 100% (47961/47961), done.

- [ ] This is a doc addition request.
- [ ] I have a fix to the document that I can paste below including example: input and output.

If you have a troubleshooting or support issue, use the following resources:

 - Ask OpenStack: http://ask.openstack.org
 - The mailing list: http://lists.openstack.org
 - IRC: 'openstack' channel on Freenode

-----------------------------------
Release: on 2019-08-15 14:54:55.656216
SHA: 2466e0dfcddb829b3fdb8f1252e04277db89f4ed
Source: https://git.openstack.org/cgit/openstack/openstack-ansible/tree/deploy-guide/source/deploymenthost.rst
URL: https://docs.openstack.org/project-deploy-guide/openstack-ansible/stein/deploymenthost.html