Bring in optional runas user for enabling plugins

Change-Id: I4410b73b497ff35fd5afc309a5372f152cdd4f9d
diff --git a/tests/pillar/rabbitmq_server.sls b/tests/pillar/rabbitmq_server.sls
index b955196..98bf4b3 100644
--- a/tests/pillar/rabbitmq_server.sls
+++ b/tests/pillar/rabbitmq_server.sls
@@ -20,6 +20,7 @@
           definition: '{"ha-mode": "all"}'
     memory:
       vm_high_watermark: 0.4
+    plugins_runas_user: root
     plugins:
     - amqp_client
     - rabbitmq_management