(whoops, I was about to make this PR on my fork instead of here!)
Oh well, anyway, since travis-ci.org is gone, we need to switch to another CI.

@Harveyt47 @mmcky I finally got 94.15% from coveralls.io: https://github.com/QuantEcon/QuantEcon.py/pull/561/checks?check_run_id=1633166620#step:7:15 -> https://coveralls.io/jobs/72880434.

My fix is to do according to this comment: coverallsapp/github-action#4 (comment).

Let me know if the commits need to be squashed. They are kind of messy.

Coverage increased (+0.1%) to 94.17% when pulling d8c4400 on rht:test-action into 08a15f5 on QuantEcon:master.

thanks @rht!. We will definitely Squash these commits. One question before we merge -- I see you added a GitHub Repo Secret for the Tokens Coveralls. Just wondering if we should use a quantecon account -- I am guessing that is a personal token?

I see you added a GitHub Repo Secret for the Tokens Coveralls.

Nope, I was in fact removing it.
According to the readme of https://github.com/AndreMiras/coveralls-python-action
this is the default value of GITHUB_TOKEN:

Default: ${{ github.token }}

Also, I removed .coveralls.yml instead, so it is no longer tied to travis-ci.

I added another commit to remove pytest since it is no longer used in the latest version of this PR.

Thanks @rht I struggled with the coveralls.io a bit. Is this still running nose and not pytest?

Yes, this is still running nose. If you want to migrate to pytest, I think we can do that in another PR.

Ready to be squashed.

Thanks @rht -- it will be nice to have tests via GitHub Actions.