Performance fix and correction for events verification post reboot

Seeing failure for event post reboot this particular test since many
test runs and manual execution as well. This turns out to be due to
fixed sleep and doing REST operation. With this changes, the test is
sanely doing the test and consitently passing on a given good driver.

This changes includes:
   - Adding new keyword in utils.robot for general usage and
     removing it from code update utils.
   - Tweaks "Verify Ping and REST Authentication" keyword

Resolves openbmc/openbmc-test-automation#115

Change-Id: Ief10e948fd03736a024a13add208de478ac9fecb
Signed-off-by: George Keishing <gkeishin@in.ibm.com>
diff --git a/extended/code_update/update_bmc.robot b/extended/code_update/update_bmc.robot
index 6c22803..6d4ca55 100644
--- a/extended/code_update/update_bmc.robot
+++ b/extended/code_update/update_bmc.robot
@@ -41,7 +41,6 @@
     Run Keyword If   '${session_active}' == '${True}'
     ...    Trigger Warm Reset via Reboot
 
-    Wait Until Keyword Succeeds
-    ...  30 min   10 sec     Check If BMC is Up
+    Check If BMC is Up    30 min   10 sec
     Sleep  1 min
     Validate BMC Version