Support for Pytest in Visual Studio has been added on Visual Studio 2019 (16.3 Preview 2)
You have to change your project’s test framework by right-clicking it and going to Properties -> Test
You can add a pytest.ini to your project to configure pytest further.
More info from MS themselves: https://devblogs.microsoft.com/python/whats-new-for-python-in-visual-studio-16-3-preview-2/