Update KVM test framework to 3.15 guest kernel

testing/testing.conf

@@ -24,11 +24,11 @@ fi
 : ${TESTDIR=/srv/strongswan-testing}
 
 # Kernel configuration
-: ${KERNELVERSION=3.13.5}
+: ${KERNELVERSION=3.15.1}
 : ${KERNEL=linux-$KERNELVERSION}
 : ${KERNELTARBALL=$KERNEL.tar.xz}
-: ${KERNELCONFIG=$DIR/../config/kernel/config-3.13}
-: ${KERNELPATCH=ha-3.13-abicompat.patch.bz2}
+: ${KERNELCONFIG=$DIR/../config/kernel/config-3.15}
+: ${KERNELPATCH=ha-3.15-ah-abicompat.patch.bz2}
 
 # strongSwan version used in tests
 : ${SWANVERSION=5.2.0}