Update py to 1.9.0

[pyup-bot]

This PR updates py from 1.8.0 to 1.9.0.

Changelog

1.9.0

==================

- Add type annotation stubs for the following modules:

* ``py.error``
* ``py.iniconfig``
* ``py.path`` (not including SVN paths)
* ``py.io``
* ``py.xml``

There are no plans to type other modules at this time.

The type annotations are provided in external .pyi files, not inline in the
code, and may therefore contain small errors or omissions. If you use ``py``
in conjunction with a type checker, and encounter any type errors you believe
should be accepted, please report it in an issue.

1.8.2

==================

- On Windows, ``py.path.local``s which differ only in case now have the same
Python hash value. Previously, such paths were considered equal but had
different hashes, which is not allowed and breaks the assumptions made by
dicts, sets and other users of hashes.

1.8.1

==================

- Handle ``FileNotFoundError`` when trying to import pathlib in ``path.common``
on Python 3.4 (207).

- ``py.path.local.samefile`` now works correctly in Python 3 on Windows when dealing with symlinks.

Links

• PyPI: https://pypi.org/project/py
• Changelog: https://pyup.io/changelogs/py/
• Docs: https://py.readthedocs.io/

[pyup-bot]

Closing this in favor of #49