Why has coverage been locked to `==4.0.3` for two years? Why not `>=4.0.0`?

If I add localstack to my pipenv, I can't lock because of this unnecessary dependency.
LOGGER = logging.getLogger(__name__)
def test_firehose_s3():
    s3_resource = aws_stack.connect_to_resource('s3')
    firehose = aws_stack.connect_to_service('firehose')
    s3_prefix = '/testdata'
    test_data = '{"test": "firehose_data_%s"}' % short_uid()
    
    stream = firehose.create_delivery_stream(
        DeliveryStreamName=TEST_FIREHOSE_NAME,
        S3DestinationConfiguration={
            'RoleARN': aws_stack.iam_resource_arn('firehose'),
            'BucketARN': aws_stack.s3_bucket_arn(TEST_BUCKET_NAME),
            'Prefix': s3_prefix
        }
    )
    assert stream
    assert TEST_FIREHOSE_NAME in firehose.list_delivery_streams()['DeliveryStreamNames']
    
    s3_resource.create_bucket(Bucket=TEST_BUCKET_NAME)
    
    firehose.put_record(
        DeliveryStreamName=TEST_FIREHOSE_NAME,
        Record={
            'Data': to_bytes(test_data)
        }
    )
    
    all_objects = testutil.list_all_s3_objects()
    testutil.assert_objects(json.loads(to_str(test_data)), all_objects)
def test_firehose_kinesis_to_s3():