iad2: have rabbitmq instances use rhos16 instead of rhos13, which was/is rhel7 based

Signed-off-by: Kevin Fenzi <kevin@scrye.com>

files/common/rhos16.repo

@@ -0,0 +1,4 @@
+[rhel8-rhos16]
+name = rhel8 openstack $basearch
+baseurl=http://infrastructure.fedoraproject.org/repo/rhel/rhel8/other/rhel-8-x86_64-openstack-16-rpms
+gpgkey=file:///etc/pki/rpm-gpg/RPM-GPG-KEY-redhat-release

roles/rabbitmq_cluster/tasks/main.yml

@@ -6,6 +6,16 @@
   - config
   - packages
   - yumrepos
+  when: ansible_distribution_major_version|int == 7
+
+- name: Install RHOSP16 repo file
+  copy: src="{{ files }}/common/rhos16.repo" dest=/etc/yum.repos.d/rhos16.repo
+  tags:
+  - rabbitmq_cluster
+  - config
+  - packages
+  - yumrepos
+  when: ansible_distribution_major_version|int == 8
 
 - name: install needed packages
   package: