Update service validator to use AuthType

Input from Gunnar Mills:
    AuthType = Session, which creates a session and uses that.
    Doing basic auth (the default) takes roughly twice as long
    per call using our webserver.

Change-Id: Iadd70858f2c5034c632e6d3916ec83963896226a
Signed-off-by: George Keishing <gkeishin@in.ibm.com>
diff --git a/redfish/dmtf_tools/Redfish_Service_Validator.robot b/redfish/dmtf_tools/Redfish_Service_Validator.robot
index 6f2eeb9..4fea84e 100644
--- a/redfish/dmtf_tools/Redfish_Service_Validator.robot
+++ b/redfish/dmtf_tools/Redfish_Service_Validator.robot
@@ -14,7 +14,7 @@
 ${rsv_dir_path}    Redfish-Service-Validator
 ${rsv_github_url}  https://github.com/DMTF/Redfish-Service-Validator.git
 ${command_string}  ${DEFAULT_PYTHON} ${rsv_dir_path}${/}RedfishServiceValidator.py
-...                --ip ${OPENBMC_HOST} --nochkcert --forceauth -u ${OPENBMC_USERNAME}
+...                --ip ${OPENBMC_HOST} --nochkcert --authtype=Session -u ${OPENBMC_USERNAME}
 ...                -p ${OPENBMC_PASSWORD} --logdir ${EXECDIR}${/}logs${/} --debug_logging
 
 *** Test Case ***