add keystone region support

Change-Id: Idc48db4db383ac793d2cafadbfcd100322df12e5
diff --git a/README.rst b/README.rst
index e14d670..b9058f1 100644
--- a/README.rst
+++ b/README.rst
@@ -16,6 +16,7 @@
       server:
         enabled: true
         version: icehouse
+        region: RegionOne
         bind:
           metadata:
             address: 10.0.106.10