Enable Vnet/Vxlan VS test (sonic-net#935)

* Enable Vnet/Vxlan test

Author: prsunny

tests/test_vxlan_tunnel.py

@@ -242,8 +242,6 @@ def get_lo(dvs):
     return lo_id
 
 
-# TODO: Please fix this test case.
-@pytest.mark.skip(reason="Starting Vxlanmgr to be merged")
 def test_vxlan_term_orch(dvs, testlog):
     tunnel_map_ids       = set()
     tunnel_map_entry_ids = set()