[bug] and_return_result_of doesn't correctly handle async methods

[jmaliksi]

    def return_value(self, *args, **kwargs):
        """Extracts the real value to be returned from the wrapping callable.

        :return: The value the double should return when called.
        """

        self._called()
>       return self._return_value(*args, **kwargs)
E       TypeError: 'coroutine' object is not callable

if you create an allowance on an async method and use and_return_result_of you get the above error. I think this specifically will only happen when the fake is expecting arguments as the default usage that and_return does hides the error by wrapping argument-less _return_value in a lambda

[toddsifleet]

I found the issue, working on a solution.