message: Fix terminology
  Reviewers: davidn, jakeh, markp
diff: @@ -159,7 +159,7 @@ tf.Dataset.batch, set `drop_remainder=True`.""".format(output_shape))
  return self._initializer
  def get_next(self):
  - """Deprecated function."""
  - raise ValueError("""Deprecated behaviour - the IPUInfeedQueue is now \
  -automatically dequeued by the loop.""")
  + """Obsolete function."""
  + raise ValueError("""`get_next()` is now obsolete as the IPUInfeedQueue is \
  +now automatically dequeued by the loop.""")
  