Bump marshmallow from 2.18.0 to 3.9.0

Bumps marshmallow from 2.18.0 to 3.9.0.

Changelog

Sourced from marshmallow's changelog.

3.9.0 (2020-10-31)

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Features:

• Add format argument to fields.Time and timeformat class Meta option (:issue:686). Thanks :user:BennyAlex for the suggestion and thanks :user:infinityxxx for the PR.

Other changes:

• Remove usage of implicit typing.Optional (:issue:1663). Thanks :user:nadega for the PR.

3.8.0 (2020-09-16)

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Features:

• Add fields.IP, fields.IPv4 and fields.IPv6 (🇵🇷1485). Thanks :user:mgetka for the PR.

Bug fixes:

• Fix typing in AwareDateTime (🇵🇷1658). Thanks :user:adithyabsk for reporting.

3.7.1 (2020-07-20)

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Bug fixes:

• fields.Boolean correctly serializes non-hashable types (🇵🇷1633). Thanks :user:jun0jang for the PR.

3.7.0 (2020-07-08)

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Deprecations:

• marshmallow.pprint is deprecated and will be removed in marshmallow 4 (:issue:1588).

Support:

• Document default_error_messages on field classes (🇵🇷1619). Thanks :user:weeix.

Bug fixes:

• Fix passing only and exclude to Nested with an ordered Schema (🇵🇷1627). Thanks :user:juannorris for the PR.

... (truncated)

Commits

• 739ec29 Bump version and update changelog
• c30d3eb Add format option for fields.time #686 (#1682)
• f37da1a Test against Python 3.9 (#1680)
• 1735d63 Bump mypy from 0.782 to 0.790
• 43db107 Fix #1663 Typing - Use explicit optional (#1666)
• 0689e55 Bump flake8 from 3.8.3 to 3.8.4
• 9e88f46 Fix watch-docs tox environment
• 51c4b6c Merge pull request #1668 from marshmallow-code/dependabot/pip/autodocsumm-0.2.1
• f2efc84 Bump autodocsumm from 0.2.0 to 0.2.1
• a207173 Bump version and update changelog
• Additional commits viewable in compare view