[tensorflow_utils.py] tensorflow 2 has no attribute named python-io anymore....
This PR adds support for certain APIs in Tensorflow 2 (tf.io.TFRecordWriter and tf.keras.utils.Progbar) and Python 3 (.items()).
Related commit:
[tensorflow_utils.py] tensorflow 2 has no attribute named python-io anymore. Progbar api has also changed. also iteritems is absolute in python3, instead there is items.