Add force tags for openpower vmi test suite

Changes:
    - Added force tag directive names

Tested:

    With --include or --exclude  options while running test suite

    Tag names:
       vmi_certificate_test
       vmi_multi_interface_test
       vmi_interface_test

Change-Id: I1879ccc211d45d52a31082e1bb2674274c577e23
Signed-off-by: George Keishing <gkeishin@in.ibm.com>
diff --git a/openpower/ext_interfaces/test_vmicert_management.robot b/openpower/ext_interfaces/test_vmicert_management.robot
index 4e6e041..db263b0 100644
--- a/openpower/ext_interfaces/test_vmicert_management.robot
+++ b/openpower/ext_interfaces/test_vmicert_management.robot
@@ -13,6 +13,8 @@
 Test Teardown     FFDC On Test Case Fail
 Suite Teardown    Suite Teardown Execution
 
+Force Tags        vmi_certificate_test
+
 
 *** Variables ***