Delete hub/tutorials/image_retraining, which has been superseded by https://colab.research.google.com/github/tensorflow/hub/blob/master/examples/colab/tf2_image_retraining.ipynb
Delete hub/tutorials/image_retraining, which has been superseded by
https://colab.research.google.com/github/tensorflow/hub/blob/master/examples/colab/tf2_image_retraining.ipynb

PiperOrigin-RevId: 286371355

tensorflow/hub,tensorflow/hub