Add optional parameter key for specifying bucket when creating credentials. (#537)
Add optional parameter key for specifying bucket when creating credentials. (#537)

This allows users to optionally specify a bucket to upload CloudBackups to.

Signed-off-by: veda <500ea1183efa14e2c444415e1014d0fe91770b5c@portworx.com>
pault84/openstorage,libopenstorage/openstorage,pault84/openstorage,libopenstorage/openstorage,libopenstorage/openstorage,pault84/openstorage