Write the configurations to a configuration file in the CRMod format
        All configurations are merged into one previor to writing to file

        Parameters
        ----------
        filename: string
            absolute or relative path to output filename (usually config.dat)

def write_crmod_config(self, filename):
        """Write the configurations to a configuration file in the CRMod format
        All configurations are merged into one previor to writing to file

        Parameters
        ----------
        filename: string
            absolute or relative path to output filename (usually config.dat)
        """
        ABMN = self._get_crmod_abmn()

        with open(filename, 'wb') as fid:
            fid.write(bytes(
                '{0}\n'.format(ABMN.shape[0]),
                'utf-8',
            ))
            np.savetxt(fid, ABMN.astype(int), fmt='%i %i')