retry on buck test failure

Change-Id: Id30a247e5b75249d06377605aa358590036cd659
diff --git a/jjb/onos/onos-verify.sh b/jjb/onos/onos-verify.sh
index 5e04c50..a26c8a0 100755
--- a/jjb/onos/onos-verify.sh
+++ b/jjb/onos/onos-verify.sh
@@ -3,4 +3,4 @@
 . tools/build/envDefaults
 echo $PATH
 onos-buck build onos $(onos-buck targets | egrep -e '-javadoc$')
-onos-buck test
+onos-buck test || onos-buck test --only-failing