Remove memcached container in cleanup-containers tool

Change-Id: Ic56b7b2fd6cd7d191cc364a37f3ebbc44950932e
Closes-Bug: #1508780

tools/cleanup-containers

@@ -22,7 +22,8 @@ containers_to_kill=(
     openvswitch_{vswitchd,db} \
     rabbitmq{,_data} \
     rsyslog \
-    swift_{account_{auditor,reaper,replicator,server},container_{auditor,expirer,replicator,server,updater},proxy_server,rsyncd}
+    swift_{account_{auditor,reaper,replicator,server},container_{auditor,expirer,replicator,server,updater},proxy_server,rsyncd} \
+    memcached
 )
 
 echo "Stopping containers..."