Update marshmallow to 3.5.2

[pyup-bot]

This PR updates marshmallow from 3.5.1 to 3.5.2.

Changelog

3.5.2

******************

Bug fixes:

- Fix typing in ``class_registry`` (:pr:`1574`). Thanks :user:`mahenzon`.

Links

• PyPI: https://pypi.org/project/marshmallow
• Changelog: https://pyup.io/changelogs/marshmallow/
• Repo: https://github.com/marshmallow-code/marshmallow

[coveralls]

Pull Request Test Coverage Report for Build 697

• 0 of 0 changed or added relevant lines in 0 files are covered.
• No unchanged relevant lines lost coverage.
• Overall coverage remained the same at 0.0%

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Totals
Change from base Build 695:	0.0%
Covered Lines:	0
Relevant Lines:	0

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💛 - Coveralls