Update CoulombMatrix featurizer

  conformers = True

  name = 'coulomb_matrix'

  def __init__(self, max_atoms, remove_hydrogens=True, randomize=True,

               n_samples=1, seed=None):

  def __init__(self, max_atoms, remove_hydrogens=False, randomize=False,

               upper_tri=False, n_samples=1, seed=None):

    self.max_atoms = int(max_atoms)

    self.remove_hydrogens = remove_hydrogens

    self.randomize = randomize

    self.upper_tri = upper_tri

    self.n_samples = n_samples

    if seed is not None:

      seed = int(seed)

        Molecule.

    """

    features = self.coulomb_matrix(mol)

    if self.upper_tri:

      features = [f[np.triu_indices_from(f)] for f in features]

    features = np.asarray(features)

    return features