Install yum utilities in openstack_hosts
Install yum utilities in openstack_hosts

Every CentOS host will need various yum utilities at some point, so
let's install it within openstack_hosts to save time later.

Change-Id: Iae2816c4d623e0f95d07871472727f77df3b4ded

openstack/openstack-ansible-openstack_hosts,openstack/openstack-ansible-openstack_hosts