[Security] Bump webargs from 4.1.2 to 5.1.3

[dependabot-preview]

Bumps webargs from 4.1.2 to 5.1.3.

Changelog

Sourced from webargs's changelog.

5.1.3 (2019-03-11)

Bug fixes:

• Fix race condition between parallel requests when the cache is used (371). Thanks ThiefMaster for reporting and fixing.

5.1.2 (2019-02-03)

Bug fixes:

• Remove lingering usages of ValidationError.status_code (365). Thanks decaz for reporting.
• Avoid AttributeError on Python<3.5.4 (366).
• Fix incorrect type annotations for error_headers.
• Fix outdated docs (367). Thanks alexandersoto for reporting.

5.1.1.post0 (2019-01-30)

• Include LICENSE in sdist (364).

5.1.1 (2019-01-28)

Bug fixes:

• Fix installing simplejson on Python 2 by distributing a Python 2-only wheel (363).

5.1.0 (2019-01-11)

Features:

• Error handlers for AsyncParser classes may be coroutine functions.
• Add type annotations to AsyncParser and AIOHTTPParser.

Bug fixes:

• Fix compatibility with Flask<1.0 (355). Thanks hoatle for reporting.
• Address warning on Python 3.7 about importing from collections.abc.

5.0.0 (2019-01-03)

Features:

• Backwards-incompatible: A 400 HTTPError is raised when an invalid JSON payload is passed. (329). Thanks zedrdave for reporting.

Other changes:

... (truncated)

Commits

• 1c43dca Bump version and update changelog
• 716bd8d Merge pull request #373 from ThiefMaster/race-conditions-are-evil-2
• e6fff23 Move import to top of file
• a4a228b Fix sharing cache when parsing in parallel
• 0e96f78 Add failing test
• dd7585c Fix missing mock call assertions
• 944d5fd Merge pull request #370 from marshmallow-code/src
• 837f2e8 Switch to src/ layout
• 9db6390 Run pre-commit autoupdate
• c7c8d5d Conditionally install flake8-bugbear
• Additional commits viewable in compare view

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[dependabot-preview]

We've just been alerted that this update fixes a security vulnerability:

Sourced from The GitHub Security Advisory Database.

High severity vulnerability that affects webargs
An issue was discovered in webargs before 5.1.3, as used with marshmallow and other products. JSON parsing uses a short-lived cache to store the parsed JSON body. This cache is not thread-safe, meaning that incorrect JSON payloads could have been parsed for concurrent requests.

Affected versions: ["< 5.1.3"]

[dependabot-preview]

Superseded by #358.