nixos-install: link to installer test

pkgs/by-name/ni/nixos-install/package.nix

@@ -7,6 +7,7 @@
   jq,
   nixos-enter,
   util-linuxMinimal,
+  nixosTests,
 }:
 substituteAll {
   name = "nixos-install";
@@ -29,6 +30,8 @@ substituteAll {
     installManPage ${./nixos-install.8}
   '';
 
+  passthru.tests.installer-simpleUefiSystemdBoot = nixosTests.installer.simpleUefiSystemdBoot;
+
   meta = {
     description = "Install bootloader and NixOS";
     homepage = "https://github.com/NixOS/nixpkgs/tree/master/pkgs/by-name/ni/nixos-install";