Fix cpp-tests memory leak

Author: halx99

tests/cpp-tests/Source/BaseTest.cpp

@@ -1,6 +1,7 @@
 /****************************************************************************
  Copyright (c) 2013-2016 Chukong Technologies Inc.
  Copyright (c) 2017-2018 Xiamen Yaji Software Co., Ltd.
+ Copyright (c) 2019-present Axmol Engine contributors (see AUTHORS.md).
 
  https://axmol.dev/
 
@@ -178,7 +179,6 @@ void TestList::runThisTest()
     auto origin      = director->getVisibleOrigin();
     deatchTableView();
     _tableView = TestCustomTableView::create(this, Size(400, visibleSize.height));
-    _tableView->retain();
     _tableView->setPosition(origin.x + (visibleSize.width - 400) / 2, origin.y);
     _tableView->setDirection(ScrollView::Direction::VERTICAL);
     _tableView->setVerticalFillOrder(TableView::VerticalFillOrder::TOP_DOWN);