*   Keras & Python API
    *   Add to Keras functionality analogous to
        `tf.register_tensor_conversion_function`.
    *   Subclassed Keras models can now be saved through
        `tf.contrib.saved_model.save_keras_model`.
    *   `LinearOperator.matmul` now returns a new `LinearOperator`.
*   New ops and improved op functionality
    *   Add a Nearest Neighbor Resize op.