Features
- Add plural forms for the `list-backup`, `list-server` and
`show-server` commands which are now `list-backups`, `list-servers`
and `show-servers`. The singular forms are retained for backward
compatibility.
- Add the `last-failed` backup shortcut which references the newest
failed backup in the catalog so that you can do:
`barman delete <SERVER> last-failed`
Bug fixes
- Tablespaces will no longer be omitted from backups of EPAS
versions 9.6 and 10 due to an issue detecting the correct version
string on older versions of EPAS.