Update requests to 2.23.0

[pyup-bot]

This PR updates requests from 2.22.0 to 2.23.0.

Changelog

### 2.23.0 ``` ------------------- **Improvements** - Remove defunct reference to `prefetch` in Session `__attrs__` (5110) **Bugfixes** - Requests no longer outputs password in basic auth usage warning. (5099) **Dependencies** - Pinning for `chardet` and `idna` now uses major version instead of minor. This hopefully reduces the need for releases everytime a dependency is updated. ```

Links

- PyPI: https://pypi.org/project/requests - Changelog: https://pyup.io/changelogs/requests/ - Docs: https://requests.readthedocs.io

[coveralls]

Pull Request Test Coverage Report for Build 1316

• 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 99.275%

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Totals
Change from base Build 1198:	0.0%
Covered Lines:	2191
Relevant Lines:	2207

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💛 - Coveralls

[pyup-bot]

Closing this in favor of #352