- Version update to 2.0.2:
* Surface fixes:
* Fixed #31 whereby I changed the boolean response in 2.0.0 to
a PAM constant. This reverts to the boolean response as
existed in v1.8.5. The result code is still stored in the
obj.code attribute.
* Added the PamAuthenticate.authenticate() method signature
and docstring to both of the new and legacy interfaces.
* Changed the PamAuthenticate.authenticate() type hinting so it
didn't interfere with the docstring.
* Under the hood changes:
* Start mocking the libpam methods so we can wholly disassociate
ourselves from the underlying system. This lets us test more
of the actual python code and lets us start injecting errors
to test for.

- Version update to 2.0.0:
* The surface functionality hasn't changed much but a few bugs
have been fixed. Under the hood, a lot has changed.
Functionality has now been moved into a class that helped with
value tracking. I planned on removing Python 2 support but
was convinced to leave it in for now as apparently there are
still a lot of python2 users.
* Most testing has moved to occur underneath tox, this is superior
as it provides for testing in a clean environment and an
installed environment.