Replaced certificate delete method from REST to BMC CLI
Replaced certificate delete method from REST to BMC CLI

Change-Id: Ia2fd728eed905e2dfd683b0e47ce4ad4cb835a51
Signed-off-by: Rahul Maheshwari <a806e6fd77e56dd64ff6084a06bbf3a5a70392ef@in.ibm.com>

openbmc/openbmc-test-automation,openbmc/openbmc-test-automation