starting with server class
adding String to Boolean conversion
parsing 'show server' and creating a Server object
parsing 'check' and assigning values
implementing CliCommand.server to get a Server object which basically represents a server state reported by barman
replacing with_wal_files boolean by options {}
updating README
replacing backup_id arg in CliCommand.backups by using opts[:backup_id]
changing CliCommand.size_in_bytes to class method
adding options hash as argument to CliCommand.server
adding class method Server.by_name
adding CliCommand.servers to get all servers
adding class Servers