nixosTests.initdb: Move code to existing postgres test

nixos/tests/initdb.nix

@@ -1,19 +0,0 @@
-import ./make-test-python.nix ({ pkgs, latestKernel ? false, ... }: {
-  name = "pg-initdb";
-
-  machine = {...}:
-    {
-      documentation.enable = false;
-      services.postgresql.enable = true;
-      services.postgresql.package = pkgs.postgresql_9_6;
-      environment.pathsToLink = [
-        "/share/postgresql"
-      ];
-    };
-
-  testScript = ''
-    machine.start()
-    machine.succeed("sudo -u postgres initdb -D /tmp/testpostgres2")
-    machine.shutdown()
-  '';
-})

nixos/tests/postgresql.nix

@@ -76,6 +76,9 @@ let
               "stat -c '%a' /var/backup/postgresql/${backupName}.sql.gz | grep 600",
           )
 
+      with subtest("Initdb works"):
+          machine.succeed("sudo -u postgres initdb -D /tmp/testpostgres2")
+
       machine.shutdown()
     '';