upload frozen requirements to release assets + add build / PyPI publish workflow

[zacharyburnett]

this PR should be kept as a draft until after #588 is merged, then rebased onto develop

changes in this PR:

• added build.yml workflow that runs on pull requests, and also on releases (when on a release it also uploads the built wheel to PyPI - this requires that a PYPI_TOKEN with push permission for this repo be added to the repo secrets in Settings)
• added steps to the end of test.yml that upload the frozen requirements.txt for that test session to two places:
  • as an artifact attached to every run
  • if triggered by a release, to the Assets section of that release
• run tests in test.yml in parallel, and with coverage
• upload coverage report to Codecov (needs CODECOV_TOKEN for this repo to be added to the repo secrets in Settings; this can be set up at codecov.io). This step can be removed if you don't want to use codecov to track coverage over time

[pep8speaks]

Hello @zacharyburnett, Thank you for updating !

• In the file docs/conf.py:

Line 59:1: E265 block comment should start with '# '
Line 120:5: E123 closing bracket does not match indentation of opening bracket's line
Line 124:1: E265 block comment should start with '# '
Line 129:1: E265 block comment should start with '# '
Line 132:1: E265 block comment should start with '# '
Line 137:1: E265 block comment should start with '# '
Line 141:1: E265 block comment should start with '# '

• In the file exoctk/__init__.py:

Line 19:1: W391 blank line at end of file

• In the file setup.py:

Line 6:2: W292 no newline at end of file

Comment last updated at 2024-02-01 17:55:04 UTC

[codecov-commenter]

Welcome to Codecov 🎉

Once you merge this PR into your default branch, you're all set! Codecov will compare coverage reports and display results in all future pull requests.

Thanks for integrating Codecov - We've got you covered ☂️