Added automation testcase for service user

    Verify Renaming Service User

Change-Id: If1f3fddea062b3c3b9d49fa760ef02ab0989be1d
Signed-off-by: manashsarma <manashsarma@in.ibm.com>
diff --git a/openpower/service_account/test_service_user.robot b/openpower/service_account/test_service_user.robot
index 2ca71f7..ee43010 100644
--- a/openpower/service_account/test_service_user.robot
+++ b/openpower/service_account/test_service_user.robot
@@ -43,6 +43,14 @@
      ...  valid_status_codes=[${HTTP_BAD_REQUEST}]
 
 
+Verify Renaming Service User
+     [Documentation]  Verify error while renaming service user via Redfish.
+
+     ${payload}=  Create Dictionary  UserName=new_service
+     Redfish.Patch  /redfish/v1/AccountService/Accounts/service  body=&{payload}
+     ...  valid_status_codes=[${HTTP_BAD_REQUEST}]
+
+
 *** Keywords ***
 
 Suite Setup Execution