Use GitHub Actions for CI

[rly]

Motivation

Fix #1551. After having done this in HDMF, this was easier than I thought!

Checklist

• Did you update CHANGELOG.md with your changes?
• Have you checked our Contributing document?
• Have you ensured the PR clearly describes the problem and the solution?
• Is your contribution compliant with our coding style? This can be checked running flake8 from the source directory.
• Have you checked to ensure that there aren't other open Pull Requests for the same change?
• Have you included the relevant issue number using "Fix #XXX" notation where XXX is the issue number? By including "Fix #XXX" you allow GitHub to close issue #XXX when the PR is merged.

[codecov]

Codecov Report

Merging #1560 (4182b9a) into dev (d901388) will not change coverage.
The diff coverage is n/a.

@@           Coverage Diff           @@
##              dev    #1560   +/-   ##
=======================================
  Coverage   90.65%   90.65%           
=======================================
  Files          25       25           
  Lines        2494     2494           
  Branches      466      466           
=======================================
  Hits         2261     2261           
  Misses        148      148           
  Partials       85       85           

Flag	Coverage Δ
integration	69.60% <ø> (ø)
unit	84.16% <ø> (ø)

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[rly]

TODO:

• Set up environment variables for deploy bot
• Write changelog
• Update required checks for merge
• Check in with NWB inspector tests
• Update docs to remove references to Azure Pipelines and CircleCI