Update conda environments

[jomey]

• Add cookiecutter library to the lock files (checks box in splash page for hackweek web template #38)
• Update Python to 3.10
• Run test pipeline for Ubuntu and macOSX
• Extend test runs for any changes to a GH action
• Add checks for build script for successful commands

[jomey]

Took a little, but this is ready for review now. The pull_request_target action is failing as expected with main currently not in good shape.

[scottyhq]

Thanks @jomey this is looking great! For the preview workflow to work as expected again, we'll need to make a small change to the following lines:

jupyterbook-template/.github/workflows/netlifypreview.yaml

Lines 14 to 16 in 200fe3c

	steps:
	- name: Checkout repository
	uses: actions/checkout@v2

To -->

    - uses: actions/checkout@v2
      with:
        ref: ${{ github.event.pull_request.head.sha }}

(I think this maybe changed accidentally in the latest revamp)...

[jomey]

Can we allow the 'merge and commit' strategy for PRs for this repo again?
I like having the individual commits for the affected files of this PR. Squashing them into one commit makes it harder to re-trace what and why files have been changed later on in my perspective. That's where concise commits and associated messages come in handy and a squash would take this away again.

[scottyhq]

Can we allow the 'merge and commit' strategy for PRs for this repo again?

Done... I like squash and merge for convenience especially with really long PRs with a bunch of commits for testing, but you're totally right that ideally we'd rebase those to maintain a more concise and logical history...