Adds vars file for centos

Deploying CentOS image was failing attempting to gather
vars.  This adds a needed variable file.

Change-Id: I136441f0711fe9b07dda6f1e9e49947e21396f30

multi-node-aio/playbooks/vars/redhat.yml

@@ -0,0 +1,16 @@
+---
+# Copyright 2019, Rackspace US, Inc.
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#     http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in witing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+ssh_service_name: sshd