Write GO DAG version and key indicating presence of GO ID in a list.

def _wr_ver_n_key(self, fout_txt, verbose):
        """Write GO DAG version and key indicating presence of GO ID in a list."""
        with open(fout_txt, 'w') as prt:
            self._prt_ver_n_key(prt, verbose)
            print('               WROTE: {TXT}'.format(TXT=fout_txt))