Clean up container on connection failure, switch to ory/dockertest on package postgresql (#5050)

plugins/database/postgresql/postgresql_test.go

@@ -53,6 +53,7 @@ func preparePostgresTestContainer(t *testing.T) (cleanup func(), retURL string)
 		defer db.Close()
 		return db.Ping()
 	}); err != nil {
+		cleanup()
 		t.Fatalf("Could not connect to PostgreSQL docker container: %s", err)
 	}