Update py to 1.7.0

[pyup-bot]

This PR updates py from 1.6.0 to 1.7.0.

Changelog

1.7.0

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

- fix 174: use ``shutil.get_terminal_size()`` in Python 3.3+ to determine the size of the
terminal, which produces more accurate results than the previous method.

- fix pytest-dev/pytest2042: introduce new ``PY_IGNORE_IMPORTMISMATCH`` environment variable
that suppresses ``ImportMismatchError`` exceptions when set to ``1``.

Links

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

[coveralls]

Coverage remained the same at 86.27% when pulling 19df413 on pyup-update-py-1.6.0-to-1.7.0 into e806b35 on master.