pass s6 scripts for menshen-agent

conf/services.d/menshen-agent/finish

+#!/bin/sh
+
+echo "Exiting menshen-agent"
+s6-svscanctl -t /var/run/s6/services

conf/services.d/menshen-agent/run

+#!/bin/sh
+
+echo "Starting menshen-agent"
+# To run, menshen_agent needs AGENT_NAME and AGENT_LOCATION (mandatory).
+# AGENT_MENSHENADDRESS and AGENT_NETDEVICE will probably need to be configured too.
+exec /usr/bin/menshen_agent