added connection pool and tests

test/orm/backend/test_result_reader.cpp

@@ -87,6 +87,7 @@ void test_result_reader::read_value(const char *id, const size_t index, utils::v
   val = "value";
 }
 utils::attribute_reader &test_result_reader::result_binder() {
-  return query_result_reader::result_binder();
+  return empty_binder_;
 }
+
 } // namespace matador::test::orm