Coulomb transformer tests breakout

import deepchem as dc

import numpy as np

def test_coulomb_fit_transformer():

  """Test coulomb fit transformer on singletask dataset."""

  n_samples = 10

  n_features = 3

  n_tasks = 1

  ids = np.arange(n_samples)

  X = np.random.rand(n_samples, n_features, n_features)

  y = np.zeros((n_samples, n_tasks))

  w = np.ones((n_samples, n_tasks))

  dataset = dc.data.NumpyDataset(X, y, w, ids)

  fit_transformer = dc.trans.CoulombFitTransformer(dataset)

  X_t = fit_transformer.X_transform(dataset.X)

  assert len(X_t.shape) == 2