47330b1732
Need to pass `cups.out` to `systemd.packages`, lest we end up with an invalid generated unit containing only directives set in the service module. This patch gives us a valid cups.service unit but, vexingly, does not fix the test failure at NixOS/nixpkgs#14748
*** NixOS *** NixOS is a Linux distribution based on the purely functional package management system Nix. More information can be found at http://nixos.org/nixos and in the manual in doc/manual.