chore: Adopt black formatting

[jfuss]

Issue #, if available:
N/A

Description of changes:
Move this repo from flake8 to black. Previous to this, developers would run make pr and handle any pylint or flake8 errors reported manually. With black, which is similar to go's fmt, will automatically format all the files for you. I also added 'pre-commit` configuration, so that way developers can install the git hooks and will ensure all files were formatted with black before doing a push.

This will align this repo with AWS SAM CLI's and provide a consistent developer experience for contribution across these repos.

Description of how you validated changes:
Ran make pr

Checklist:

• Write/update tests
• make pr passes
• Update documentation
• Verify transformed template deploys and application functions as expected
• Add/update example to examples/2016-10-31

By submitting this pull request, I confirm that my contribution is made under the terms of the Apache 2.0 license.

[codecov-io]

Codecov Report

Merging #1322 into develop will not change coverage.
The diff coverage is 91.66%.

@@           Coverage Diff            @@
##           develop    #1322   +/-   ##
========================================
  Coverage    94.41%   94.41%           
========================================
  Files           78       78           
  Lines         4529     4529           
  Branches       903      903           
========================================
  Hits          4276     4276           
  Misses         119      119           
  Partials       134      134

Impacted Files	Coverage Δ
samtranslator/model/naming.py	100% <ø> (ø)	⬆️
samtranslator/public/sdk/resource.py	100% <ø> (ø)	⬆️
samtranslator/validator/validator.py	95.65% <ø> (ø)	⬆️
samtranslator/model/tags/resource_tagging.py	100% <ø> (ø)	⬆️
...translator/policy_template_processor/exceptions.py	100% <ø> (ø)	⬆️
samtranslator/public/sdk/parameter.py	0% <ø> (ø)	⬆️
samtranslator/public/translator.py	0% <ø> (ø)	⬆️
samtranslator/plugins/globals/globals_plugin.py	100% <ø> (ø)	⬆️
samtranslator/public/sdk/template.py	100% <ø> (ø)	⬆️
samtranslator/plugins/exceptions.py	85.71% <0%> (ø)	⬆️
... and 57 more

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[ShreyaGangishetty]

@jfuss I have rebased this PR to to merge into develop. Could you please resolve the merge conflicts?

[jfuss]

@ShreyaGangishetty Rebased with HEAD of develop.

On a side note: If the intention is for developers to put code into develop, you should consider moving the default branch to develop instead of master. I expect the default branch to be where code will end up.

[ShreyaGangishetty]

@jfuss Thank you for this suggestion! We had our official SAM documentation in Github until recently. We didn't want to redirect everyone to our develop documentation until the documentation is made official through releases. Now that we have AWS SAM specification it is a good idea to make develop as the default branch

[ShreyaGangishetty]

Resolved the merge conflicts and this PR looks good to me. Thank you for contributing this!!