Scenario test for vpnaas: ipsec-site-connection
Scenario test for vpnaas: ipsec-site-connection

The test verifies that it is possible to establish a vpn
connection between two sites. And then it performs basic
connectivity test, it pings instance of site2 from instance
of site1 and vice versa.

Change-Id: Id0edfda58d6cb163c60a62802a2e852ca211f0fe

cisco-openstack/tempest,cisco-openstack/tempest,CiscoSystems/tempest,CiscoSystems/tempest