[neon] 15.10 -> 16.04 upgrade testing

[Jonathan Riddell]

The bits should now be in place to test 15.10 -> 16.04 foundation upgrade

add this to the end of /etc/hosts
    212.47.227.29 releases.neon.kde.org.uk

make sure your current install is updated
   apt update; apt full-upgrade

then run
   do-release-upgrade

Next step, which I may or may not get round to, is GUI using
plasma-discover-updater

Anyway if anyone wants to test it out let me know how you get on

Jonathan