Save subtitle file.

def save(self):
        """Save subtitle file."""
        try:
            # ensure file is encoded properly while saving
            self.project.main_file.encoding = 'utf_8'
            self.project.save_main()
            if self.fix:
                LOGGER.info("Saved changes to '%s'", self.filename)
        except:  # pylint: disable=W0702
            LOGGER.error("Unable to save '%s'", self.filename)
            sys.exit(1)