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/redfish/managers/test_bmc_ipv6.robot b/redfish/managers/test_bmc_ipv6.robot
index 04853cf..7cbdb41 100644
--- a/redfish/managers/test_bmc_ipv6.robot
+++ b/redfish/managers/test_bmc_ipv6.robot
@@ -12,7 +12,7 @@
 Test Teardown  Test Teardown Execution
 Suite Setup    Suite Setup Execution
 
-Force Tags     BMC_IPv6
+Test Tags     BMC_IPv6
 
 *** Variables ***
 ${test_ipv6_addr}          2001:db8:3333:4444:5555:6666:7777:8888