Boto3, s3 folder not getting deleted

I have a directory in my s3 bucket 'test', I want to delete this directory. This is what I'm doing

s3 = boto3.resource('s3')
s3.Object(S3Bucket,'test').delete()

and getting response like this

{'ResponseMetadata': {'HTTPStatusCode': 204, 'HostId': '************', 'RequestId': '**********'}}

but my directory is not getting deleted!

I tried with all combinations of '/test', 'test/' and '/test/' etc, also with a file inside that directory and with empty directory and all failed to delete 'test'.