message: Deprecate IgniteDataset
  IgniteDataset implementation has not been maintained for quite some time
  and it may not working anymore. This PR starts the process of deprecation.
  We will remove IgniteDataset in future releases.
diff: @@ -18,6 +18,7 @@ import abc
  import socket
  import ssl
  import struct
  +import warnings
  import tensorflow as tf
  @@ -25,6 +26,12 @@ from tensorflow import dtypes
  from tensorflow.compat.v1 import data
  from tensorflow_io.python.ops import core_ops
  +warnings.warn(
  + "implementation of IgniteDataset has been "
  + "deprecated and will be removed in future releases",
  + DeprecationWarning,
  +)
  +
  class Readable(metaclass=abc.ABCMeta):
  """Readable abstract class that exposes methods to do reading-related
  