Switch from Force Tags to Test Tags

Force Tags is deprecated in Robot 7.0 and will eventually
warn and then after that stop working. Test Tags performs
the same function per docs.

Change-Id: I7cf305754b247b995a05d8da3b9de9ed613ecae2
Signed-off-by: Matt Fischer <matthew.fischer@hpe.com>
diff --git a/network/test_bmc_dhcp_conf.robot b/network/test_bmc_dhcp_conf.robot
index 06e341b..4a99697 100644
--- a/network/test_bmc_dhcp_conf.robot
+++ b/network/test_bmc_dhcp_conf.robot
@@ -8,7 +8,7 @@
 Suite Setup            Suite Setup Execution
 Suite Teardown         Run Keywords  Restore Configuration  AND Redfish.Logout
 
-Force Tags             BMC_DHCP_Conf
+Test Tags             BMC_DHCP_Conf
 
 *** Variables ***