testing: Add ikev2/rw-sig-auth scenario

testing/tests/ikev2/rw-sig-auth/pretest.dat

@@ -0,0 +1,12 @@
+moon::iptables-restore < /etc/iptables.rules
+carol::iptables-restore < /etc/iptables.rules
+dave::iptables-restore < /etc/iptables.rules
+moon::ipsec start
+carol::ipsec start
+dave::ipsec start
+carol::sleep 1
+carol::ipsec up alice
+carol::ipsec up venus
+dave::ipsec up alice
+dave::ipsec up venus
+dave::sleep 1