Makes all folders declared in the config if they
        do not exist.

def make_required_folders(self):
        """Makes all folders declared in the config if they
        do not exist.
        """
        for folder in [
            self.pending_folder,
            self.usb_incoming_folder,
            self.outgoing_folder,
            self.incoming_folder,
            self.archive_folder,
            self.tmp_folder,
            self.log_folder,
        ]:
            if not os.path.exists(folder):
                os.makedirs(folder)