Test the update of multiple channels
Test the update of multiple channels

Make sure that `nix-channel --update` won’t accidentaly remove one

rycee/nix,rycee/nix,NixOS/nix,NixOS/nix,rycee/nix,NixOS/nix,NixOS/nix,rycee/nix,rycee/nix,NixOS/nix