[Merge] lp:~mterry/update-notifier/no-gdu into lp:update-notifier

[Andy Whitcroft]

Ok following that I have built this and installed it locally.  It is detecting both USB and CDROM devices with packages on (alternate images).
-- 
https://code.launchpad.net/~mterry/update-notifier/no-gdu/+merge/116333
Your team Ubuntu Core Development Team is requested to review the proposed merge of lp:~mterry/update-notifier/no-gdu into lp:update-notifier.