Handling continuously failing test cases while running entire test bucket.

This change includes:
       - Added known_issue tag for test cases failing due to existing issues.
         And where fix for the issue is expected to take little long time.
       - With each tag addition also added github issue number.

Benefits:
       - Failing test cases can be excluded while running entire bucket
         using --exclude known_issue as suffix
       - Continuously failing test cases will have related issue number
         in document section.

Change-Id: I18c40b97a25eff947a5922e4abfacde07fe19a6b
Signed-off-by: Rahul Maheshwari <rahulmaheshwari@in.ibm.com>
diff --git a/tests/test_warmreset.robot b/tests/test_warmreset.robot
index 5f38d05..6009cb0 100644
--- a/tests/test_warmreset.robot
+++ b/tests/test_warmreset.robot
@@ -18,6 +18,10 @@
 *** Test Cases ***
 
 Test WarmReset via REST
+    [Documentation]   This testcase is to verify warm reset using REST.
+    ...               Existing Issue: https://github.com/openbmc/openbmc/issues/519
+    [Tags]  known_issue
+
     ${warm_test_file}=  Set Variable    /tmp/before_warmreset
     Open Connection And Log In
     ${stdout}   ${stderr}   ${rc}=