misc: add ikev2 tests usecases

Type: test
Ticket: VPP-1893

Change-Id: Ib6ffd00e73f7110bf9e702f4a0fd5c68395d6786
Signed-off-by: Filip Tehlar <ftehlar@cisco.com>
diff --git a/extras/strongswan/configs/responder_vrf/ipsec.secrets b/extras/strongswan/configs/responder_vrf/ipsec.secrets
new file mode 100644
index 0000000..adcf951
--- /dev/null
+++ b/extras/strongswan/configs/responder_vrf/ipsec.secrets
@@ -0,0 +1 @@
+: PSK 'Vpp123'