Capture Heroku database backup.

def capture_heroku_database(self):
        """ Capture Heroku database backup. """
        self.print_message("Capturing database backup for app '%s'" % self.args.source_app)
        args = [
            "heroku",
            "pg:backups:capture",
            "--app=%s" % self.args.source_app,
        ]
        if self.args.use_pgbackups:
            args = [
                "heroku",
                "pgbackups:capture",
                "--app=%s" % self.args.source_app,
                "--expire",
            ]
        subprocess.check_call(args)