Dynamips.create_nio is async def while BaseManager.create_nio is a sync
def. The previous fix only added the extra 'node' argument but did not
await the resulting coroutine, causing 'was never awaited' warnings and
passing a coroutine object instead of an NIO instance to the binding
dispatch. Add 'await' on the Dynamips branch. Test updated to verify
both the async nature and the parameter count.
4e30b6905a