Separate double tagged test case from basic Trellis topology

Also add a cleanup script to reset the system

Change-Id: I0a0d70ab412326fad77cb7bb11a6053f64181394
diff --git a/trellis/cleanup b/trellis/cleanup
new file mode 100755
index 0000000..d692577
--- /dev/null
+++ b/trellis/cleanup
@@ -0,0 +1,9 @@
+#!/bin/bash
+
+if [[ $EUID -ne 0 ]]; then
+   echo "This script must be run as root"
+   exit 1
+fi
+
+mn -c
+killall dhcpd dhclient zebra bgpd