Add tests

[saulshanabrook]

This fixes #40 by adding jest + puppeteer tests that launch jupyterlab and verify that the metadata plugin works.

• Prints build logs if build fails
• Takes screenshots if tests fails and posts as action archive, using https://yarnpkg.com/en/package/@rws-air/jestscreenshot

[saulshanabrook]

These tests are passing locally but failing in CI. I want to take a screenshot in CI and post it somehow for debugging. Prior art: argos-ci/jest-puppeteer#131 (comment) puppeteer/puppeteer#478

[saulshanabrook]

I keep getting this error where datasets is selected but not clicked somehow:

This happens consistently in CI and inconsistently locally