Summary:
Python 3.8 provides the (poorly named)
unittest.IsolatedAsyncioTestCase base class that gives each test an
asyncio event loop and runs it. This allows us to write async
integration tests, required to use modern Thrift Python.
Reviewed By: genevievehelsel
Differential Revision: D21955584
fbshipit-source-id: 8366dc7c72b31e1667e72fe1e359587b74e2c614