Finish coverage reporting in kernel.

    The coverage should previously have been started with
    setup_coverage.

def teardown_coverage(config, kernel, output_loc=None):
    """Finish coverage reporting in kernel.

    The coverage should previously have been started with
    setup_coverage.
    """
    language = kernel.language
    if language.startswith('python'):
        # Teardown code does not require any input, simply execute:
        msg_id = kernel.kc.execute(_python_teardown)
        kernel.await_idle(msg_id, 60)  # A minute should be plenty to write out coverage

        # Ensure we merge our data into parent data of pytest-cov, if possible
        cov = get_cov(config)
        _merge_nbval_coverage_data(cov)

    else:
        # Warnings should be given on setup, or there might be no teardown
        # for a specific language, so do nothing here
        pass