Feature Request

Add optional uploading of the code coverage report to codecov.io

Sample change to `.github/workflows/test.yml`
```
<       - run: pipenv run pytest --cov --cov-fail-under=100
---
>       - run: pipenv run pytest --cov --cov-fail-under=100 --cov-report=xml
>
>       - name: Upload Coverage to Codecov
>         uses: codecov/codecov-action@v1
```