radosgw-admin user create needs better documentation
Running `create user` against an existing user ID adds a key and secret to the UID, however the documentation is not clear on this. Specifically, the http://docs.ceph.com/docs/master/radosgw/adminops/ page calls out a 409 error response:
Description: Attempt to create existing user.
Code: 409 Conflict
This should be more clear in the documentation.