Wrap coroutines

[iho]

Hi!
https://github.com/jlhutch/pylru/blob/master/pylru.py#L549
value = func(*args, **kwargs)
For python3.4 need check if is coroutine and add yield from
value = yield from func(*args, **kwargs)

if asyncio.iscoroutinefunction(expect_handler)

But maybe it will anyway raise error on python 2.

[jlhutch]

Just closing old issues that, for whatever reason, never went anywhere. Please feel free to open the issue again if there is still something that needs resolved. Thanks.