New testcases for service root

Changes:
    - Added New test case:
      Verify Service Root Unsupported Methods

Added Test cases on redfish/service_root/test_service_root.robot

Tested: Ran and Tested on BMC Environment

Change-Id: I1715ed2ea31e9741ff0b888a77e3c44c0a5b1158
Signed-off-by: Nandakumar B <nandakumarb@ami.com>
diff --git a/redfish/service_root/test_service_root.robot b/redfish/service_root/test_service_root.robot
index 1a7888c..d28212f 100644
--- a/redfish/service_root/test_service_root.robot
+++ b/redfish/service_root/test_service_root.robot
@@ -129,6 +129,25 @@
     Redfish.Logout
     Valid Length  dead_resources  max_length=0
 
+Verify Service Root Unsupported Methods
+    [Documentation]  Verify Unsupported methods of service root
+    [Tags]  Verify_Service_Root_Unsupported_Methods
+
+    # Put operation on Service Root
+    Redfish.Put  /redfish/v1
+    ...  valid_status_codes=[${HTTP_METHOD_NOT_ALLOWED}]
+
+    # Post operation on Service Root
+    Redfish.Post  /redfish/v1/
+    ...  valid_status_codes=[${HTTP_METHOD_NOT_ALLOWED}]
+
+    # Delete operation on Service Root
+    Redfish.Delete  /redfish/v1
+    ...  valid_status_codes=[${HTTP_METHOD_NOT_ALLOWED}]
+
+    # Patch operation on Service Root
+    Redfish.Patch  /redfish/v1
+    ...  valid_status_codes=[${HTTP_METHOD_NOT_ALLOWED}]
 
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