netdata: reference nixos tests

pkgs/tools/system/netdata/default.nix

@@ -1,6 +1,7 @@
 { stdenv, callPackage, fetchFromGitHub, autoreconfHook, pkgconfig
 , CoreFoundation, IOKit, libossp_uuid
 , curl, libcap,  libuuid, lm_sensors, zlib, fetchpatch
+, nixosTests
 , withCups ? false, cups
 , withDBengine ? true, libuv, lz4, judy
 , withIpmi ? (!stdenv.isDarwin), freeipmi
@@ -71,6 +72,8 @@ in stdenv.mkDerivation rec {
     rm -r $out/sbin
   '';
 
+  passthru.tests.netdata = nixosTests.netdata;
+
   meta = {
     description = "Real-time performance monitoring tool";
     homepage = "https://my-netdata.io/";