airsonic: add test for module

pkgs/servers/misc/airsonic/default.nix

@@ -1,4 +1,4 @@
-{ lib, stdenv, fetchurl }:
+{ lib, stdenv, fetchurl, nixosTests }:
 
 stdenv.mkDerivation rec {
   pname = "airsonic";
@@ -14,6 +14,10 @@ stdenv.mkDerivation rec {
     cp "$src" "$out/webapps/airsonic.war"
   '';
 
+  passthru.tests = {
+    airsonic-starts = nixosTests.airsonic;
+  };
+
   meta = with lib; {
     description = "Personal media streamer";
     homepage = "https://airsonic.github.io";