CUPS in a snap: Need to create system group "lpadmin"

[Till Kamppeter]

Hi,

I am currently snapping CUPS (both for server and for desktop/phone 
printing needs) and testing it on Ubuntu Core.

Here I have found out that there is no "lpadmin" system group. Now I 
want to know how to create system groups and users out of a snap, so 
that they get created on installation and removed on uninstall of the 
snap (and conserved during an update of the snap).

    Till