__init__ inherited from object fails required_args() on Python-2.7

[ccxcz]

On Python 2.7 getargspec() fails on default __init__ method. This in turn triggers bug #1655. The required_args() function can use target.__init__ is object.__init__ to detect this case.
Test for checking correct result is provided in https://github.com/ccxcz/hypothesis/tree/check-default-init

[ccxcz]

Another way this breaks is on old-style classes that don't have to have init attribute at all. Checking with hasattr(target, '__init__') would work in that case.

[Zac-HD]

Gah, I'm so sick of Python 2... thanks for the report though 👍