Adding more aggressive and thorough implementation of wipe-out command.

Change-Id: I828ccdc994a490e17c2806d27aa36460da10f795
diff --git a/tools/test/bin/onos-mininet b/tools/test/bin/onos-mininet
index 5bcd2f5..5f11fd0 100755
--- a/tools/test/bin/onos-mininet
+++ b/tools/test/bin/onos-mininet
@@ -44,6 +44,10 @@
     "
     ;;
 
+attach)
+    $mininet -x
+    ;;
+
 start)
     ssh $remote "rm -f $log; echo logfile flush 1 > ~/.screenrc"
     (