def cover(session):
    """Run the final coverage report.
    This outputs the coverage report aggregating coverage from the unit
    test runs (not system test runs), and then erases coverage data.
    """
    session.interpreter = 'python3.6'
    session.install('coverage', 'pytest-cov')
    session.run('coverage', 'report', '--show-missing', '--fail-under=100')
    session.run('coverage', 'erase')
Run the final coverage report.
    This outputs the coverage report aggregating coverage from the unit
    test runs (not system test runs), and then erases coverage data.