Add Codecov and its badge to GitHub Action

[EV9H]

Details and Assumptions

This issue corresponds to the Codecov requirements:

• Add Codecov to your GitHub Action. I have already added the CODECOV_TOKEN to your repo so you just need to reference it in your GitHub Action.

• Add a Codecov badge to your README.mdfile so that everyone will know how much coverage your code has.

  Acceptance Criteria

  Given the above is configured
  When submitting a PR
  Then one can see the Codecov reported on the build, and the badge reflecting that.