Close connection to base DB after cleanup

When running multiple quick tests in parallel it's possible to get a connection failure due to too many clients connected.

docker-compose.yml

@@ -23,7 +23,6 @@ services:
       - "-c"
       - "log_statement=all"
       - "-c"
-      - "max_connections=1000"
+      - "max_connections=100"
     ports:
       - "5433:5432"
-

testdb.go

@@ -154,6 +154,8 @@ func create(t testing.TB, conf Config, migrator Migrator) (*Config, *sql.DB) {
 	}
 
 	t.Cleanup(func() {
+		defer baseDB.Close()
+
 		// Close the testDB
 		if err := db.Close(); err != nil {
 			t.Fatalf("could not close test database: '%s': %s", instance.Database, err)

testdb_test.go

@@ -104,12 +104,12 @@ func TestExtensionsInstalled(t *testing.T) {
 }
 
 // These two tests should show that creating many different testdbs in parallel
-// is quite fast. Each of the tests creates and destroys 10 databases.
+// is quite fast. Each of the tests creates and destroys 50 databases.
 func TestParallel1(t *testing.T) {
 	t.Parallel()
 	ctx := context.Background()
 
-	for i := 0; i < 10; i++ {
+	for i := 0; i < 50; i++ {
 		t.Run(fmt.Sprintf("subtest_%d", i), func(t *testing.T) {
 			t.Parallel()
 			db := New(t)