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.
streams = dynamodbstreams.list_streams()
    ddb_event_source_arn = None
    for stream in streams['Streams']:
        if stream['TableName'] == TEST_TABLE_NAME:
            ddb_event_source_arn = stream['StreamArn']
    assert ddb_event_source_arn
    
    zip_file = testutil.create_lambda_archive(load_file(TEST_LAMBDA_PYTHON), get_content=True,
        libs=TEST_LAMBDA_LIBS, runtime=LAMBDA_RUNTIME_PYTHON27)
    testutil.create_lambda_function(func_name=TEST_LAMBDA_NAME_DDB,
        zip_file=zip_file, event_source_arn=ddb_event_source_arn, runtime=LAMBDA_RUNTIME_PYTHON27)
    
    assert_raises(Exception, testutil.create_lambda_function, func_name=TEST_LAMBDA_NAME_DDB,
        zip_file=zip_file, event_source_arn=ddb_event_source_arn, runtime=LAMBDA_RUNTIME_PYTHON27)
    
    kinesis_event_source_arn = kinesis.describe_stream(
        StreamName=TEST_LAMBDA_SOURCE_STREAM_NAME)['StreamDescription']['StreamARN']
    testutil.create_lambda_function(func_name=TEST_LAMBDA_NAME_STREAM,
        zip_file=zip_file, event_source_arn=kinesis_event_source_arn, runtime=LAMBDA_RUNTIME_PYTHON27)
    
    sqs_queue_info = testutil.create_sqs_queue(TEST_LAMBDA_NAME_QUEUE)
    testutil.create_lambda_function(func_name=TEST_LAMBDA_NAME_QUEUE,
        zip_file=zip_file, event_source_arn=sqs_queue_info['QueueArn'], runtime=LAMBDA_RUNTIME_PYTHON27)
    
    num_events_ddb = 15
    num_put_new_items = 5
    num_put_existing_items = 2
    num_batch_items = 3
    num_updates_ddb = num_events_ddb - num_put_new_items - num_put_existing_items - num_batch_items