Add test-coverage report to continuous integration pipeline

[brylie]

We are currently using CodeClimate for quality review in our pull requests. CodeClimate can monitor test coverage if we configure our project correctly.

Task

• [ ] enable project test coverage auditing with coverage.py
• [ ] configure the necessary environment variable for CodeClimate "reporter ID" (done by. @brylie)
• [ ] follow the CodeClimate instructions for setting up GitHub Actions to generate a coverage report - with adaptations for Python

Example configuration

Something similar to the following may be all that is needed to enable test reporting in our project.

coverage:
    needs: [ test ]
    name: coverage
    runs-on: ubuntu-latest
    steps:
    - uses: actions/checkout@master
    - uses: actions/setup-python@master
      with:
        python-version: '3.10'
    - run: poetry install
    - run: coverage run -m pytest