Update patsy to 0.5.2

[pyup-bot]

This PR updates patsy from 0.4.1 to 0.5.2.

Changelog

0.5.2

------

* Fix some deprecation warnings associated with importing from the `collections`
module (rather than `collections.abc`) in Python 3.7+.

0.5.1

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* The Python 3.6.7 and 3.7.1 point releases changed the standard
tokenizer module in a way that broke patsy. Updated patsy to work
with these point releases. (See `131
<https://github.com/pydata/patsy/pull/131>`__ for details.)

0.5.0

------

* Dropped support for Python 2.6 and 3.3.
* Update to keep up with ``pandas`` API changes
* More consistent handling of degenerate linear constraints in
:meth:`DesignInfo.linear_constraint` (`89
<https://github.com/pydata/patsy/issues/89>`__)
* Fix a crash in ``DesignMatrix.__repr__`` when ``shape[0] == 0``

Links

• PyPI: https://pypi.org/project/patsy
• Changelog: https://pyup.io/changelogs/patsy/
• Repo: https://github.com/pydata/patsy