This plugin neatly integrates into ep-lites's user interface, displaying some information about what software is running on the server, including ep-lite's git revision (it's a link taking you to the commit on github!).
More things to come, if people ask for it...
On the command line, run
npm install ep_infopanel. Or, browse to
http://yourEtherpadliteInstan.ce/admin/plugins, search for
ep_infopanel and click install.
After restarting the server, the plugin takes effect.