Typo in backup-create

[Mat Lowery]

$ trove help backup-create
usage: trove backup-create <name> <instance>
                           [--description <description>] [--parent <parent>]

Creates a backup.

Positional arguments:
  <name> Name of the backup.
  <instance> UUID of the instance.

Optional arguments:
  --description <description>
                        An optional description for the backup.
  --parent <parent> Optional UUID of the parent backup to preform an
                        incremental backup from.

"preform" should be "perform". Also, consider the following alternative wording:

"Optional UUID of the parent backup from which to perform an incremental backup."

[Ivan Kolodyazhny (e0ne)]

Typo is already fixed in master