Test coverage with codecov

If codecov is set to "y", pytest-cov is added as a development dependency, and make test will run the tests and output a coverage report as coverage.xml. If include_github_actions is set to "y", coverage tests with codecov are added to the CI/CD pipeline. To enable this, sign up at codecov.io with your GitHub account. Additionally, a codecov.yaml file is created, with the following defaults:

# Badge color changes from red to green between 70% and 100%
# PR pipeline fails if codecov falls with 1%

coverage:
  range: 70..100
  round: down
  precision: 1
  status:
    project:
      default:
        target: auto
        threshold: 1%

# Ignoring Paths
# --------------
# which folders/files to ignore
ignore:
  - "foo/bar.py"