Async xUnit async unit tests are not visible

I use Visual Studio 2015 Ultimate, I wrote some unit test (I use xUnit 2.1.0.3179, it allow for this signature):

public async Task MyTest()

instead of standard unit test signature

public void MyTest()

but these unit tests are not visible in Visual Studio (code lens) and in Test Explorer. Of course I rebuild solution without any error :)

Is there any possibility to have the same feature like tests with standard signature? Maybe there is any VS extension?