Rename  websso to federation

Change-Id: Ib91329fcaf0f65f66bbea9ebbc68694adce7602f
diff --git a/README.rst b/README.rst
index 257037d..10d0a0c 100644
--- a/README.rst
+++ b/README.rst
@@ -333,7 +333,7 @@
         - password
         - token
         - saml2
-        websso:
+        federation:
           protocol: saml2
           remote_id_attribute: Shib-Identity-Provider
           federation_driver: keystone.contrib.federation.backends.sql.Federation