Deprecation wrapper

def linear_extrapolation_plot(*args, **kwargs):
  """Deprecation wrapper"""
  warnings.warn("`linear_extrapolation_plot` has moved to "
                "`cleverhans.plot.pyplot_image`. "
                "cleverhans.utils.linear_extrapolation_plot may be removed on "
                "or after 2019-04-24.")
  # pylint:disable=line-too-long
  from cleverhans.plot.pyplot_image import linear_extrapolation_plot as new_linear_extrapolation_plot
  return new_linear_extrapolation_plot(*args, **kwargs)