nixos/iodine: add test

pkgs/tools/networking/iodine/default.nix

@@ -1,4 +1,4 @@
-{ stdenv, fetchFromGitHub, zlib, nettools }:
+{ stdenv, fetchFromGitHub, zlib, nettools, nixosTests }:
 
 stdenv.mkDerivation rec {
   pname = "iodine";
@@ -19,6 +19,10 @@ stdenv.mkDerivation rec {
 
   installFlags = [ "prefix=\${out}" ];
 
+  passthru.tests = {
+    inherit (nixosTests) iodine;
+  };
+
   meta = {
     homepage = http://code.kryo.se/iodine/;
     description = "Tool to tunnel IPv4 data through a DNS server";