message: Use fetch_spiral_2d in the doc
diff: @@ -17,9 +17,8 @@ As a by-product, we produce the persistence diagram of the merge tree of the ini
  :include-source:
  import gudhi
  - f = open(gudhi.__root_source_dir__ + '/data/points/spiral_2d.csv', 'r')
  - import numpy as np
  - data = np.loadtxt(f)
  + from gudhi.datasets.remote import fetch_spiral_2d
  + data = fetch_spiral_2d()
  import matplotlib.pyplot as plt
  plt.scatter(data[:,0],data[:,1],marker='.',s=1)
  plt.show()
  