Load a CRMod configuration file

        Parameters
        ----------
        filename: string
            absolute or relative path to a crmod config.dat file

def load_crmod_config(self, filename):
        """Load a CRMod configuration file

        Parameters
        ----------
        filename: string
            absolute or relative path to a crmod config.dat file

        """
        with open(filename, 'r') as fid:
            nr_of_configs = int(fid.readline().strip())
            configs = np.loadtxt(fid)
            print('loaded configs:', configs.shape)
            if nr_of_configs != configs.shape[0]:
                raise Exception(
                    'indicated number of measurements does not equal ' +
                    'to actual number of measurements')
            ABMN = self._crmod_to_abmn(configs[:, 0:2])
            self.configs = ABMN