Support up-to-date `botocore`

[jakob-keller]

Description of Change

This PR intends to improve general compatibility of aiobotocore within the Python ecosystem by bumping the dependency specification of botocore, as well as boto3 and awscli.

Assumptions

Upstream diff contains minor changes that require adjustments to the aiobotocore codebase.

Checklist for All Submissions

• [x] I have added change info to CHANGES.rst
• [x] If this is resolving an issue (needed so future developers can determine if change is still necessary and under what conditions) (can be provided via link to issue with these details): closes #1114
  • [ ] Detailed description of issue
  • [ ] Alternative methods considered (if any)
  • [ ] How issue is being resolved
  • [ ] How issue can be reproduced
• [ ] If this is providing a new feature (can be provided via link to issue with these details):
  • [ ] Detailed description of new feature
  • [ ] Why needed
  • [ ] Alternatives methods considered (if any)

Checklist when updating botocore and/or aiohttp versions

• [x] I have read and followed CONTRIBUTING.rst
• [x] I have updated test_patches.py where/if appropriate (also check if no changes necessary)
• [x] I have ensured that the awscli/boto3 versions match the updated botocore version

[codecov[bot]]

Codecov Report

Attention: Patch coverage is 80.00000% with 1 line in your changes missing coverage. Please review.

Project coverage is 86.33%. Comparing base (ea86e2b) to head (1c99b02). Report is 11 commits behind head on master.

Files	Patch %	Lines
aiobotocore/signers.py	66.66%	1 Missing :warning:

Additional details and impacted files

```diff @@ Coverage Diff @@ ## master #1115 +/- ## ========================================== - Coverage 86.34% 86.33% -0.01% ========================================== Files 62 62 Lines 5910 5913 +3 ========================================== + Hits 5103 5105 +2 - Misses 807 808 +1 ``` | [Flag](https://app.codecov.io/gh/aio-libs/aiobotocore/pull/1115/flags?src=pr&el=flags&utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=aio-libs) | Coverage Δ | | |---|---|---| | [unittests](https://app.codecov.io/gh/aio-libs/aiobotocore/pull/1115/flags?src=pr&el=flag&utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=aio-libs) | `86.33% <80.00%> (-0.01%)` | :arrow_down: | Flags with carried forward coverage won't be shown. [Click here](https://docs.codecov.io/docs/carryforward-flags?utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=aio-libs#carryforward-flags-in-the-pull-request-comment) to find out more.

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[jakob-keller]

@thehesiod: Thanks for the quick merge and release!

[tgpfeiffer]

Thank you for the upgrade!