Update databases/py-barman to 1.5.0.

-  Add support for the get-wal command which allows users to fetch any
    WAL file from the archive of a specific server
-  Add support for retry hook scripts, a special kind of hook scripts
    that Barman tries to run until they succeed
-  Add active configuration option for a server to temporarily disable
    the server by setting it to False
-  Add barman_lock_directory global option to change the location of
    lock files (by default: 'barman_home')
-  Execute the full suite of checks before starting a backup, and skip
    it in case one or more checks fail
-  Forbid to delete a running backup
-  Analyse include directives of a PostgreSQL server during backup and
    recover operations
-  Add check for conflicting paths in the configuration of Barman, both
    intra (by temporarily disabling a server) and inter-server (by
    refusing any command, to any server).
-  Add check for wal_level
-  Add barman-wal-restore script to be used as restore_command on a
    standby server, in conjunction with barman get-wal
-  Implement a standard and consistent policy for error management
-  Improved cache management of backups
-  Improved management of configuration in unit tests
-  Tutorial and man page sources have been converted to Markdown format
-  Add code documentation through Sphinx
-  Complete refactor of the code responsible for managing the backup
    and the recover commands
-  Changed internal directory structure of a backup
-  Introduce copy_method option (currently fixed to rsync)
-  Bug fixes:
    -  Manage options without '=' in PostgreSQL configuration files
    -  Preserve Timeline history files (Fixes: #70)
    -  Workaround for rsync on SUSE Linux (Closes: #13 and #26)
    -  Disables dangerous settings in postgresql.auto.conf
        (Closes: #68)
    -  Fixed error in WAL rate calculation

(fhajny)