Ability to create and manage Subusers

[drakonstein]

There are a couple references to subusers in the code, but none of them supply a function to create, delete, or rekey a subuser.

[hrchu]

How about this? https://github.com/twonote/radosgw-admin4j/blob/master/README.md#user-management

[drakonstein]

Like that, but that's a java library instead of a python library. It will help to use the same API calls to radosgw in a python way. Thank you.

[valerytschopp]

Unfortunately the subuser management functionalities are still missing.
I currently don't have time to implement this myself, but fell free to submit a pull request.

[liammonahan]

Just a note that https://github.com/UMIACS/rgwadmin has support for subuser management if you're looking for this functionality in a Python library.