entirely.
    *   Remove `tf.contrib.timeseries` dependency on TF distributions.
    *   Replace contrib references with `tf.estimator.experimental.*` for apis
        in `early_stopping.py`.

*   `tf.estimator`:

    *   Premade estimators in the tf.estimator.DNN/Linear/DNNLinearCombined
        family have been updated to use `tf.keras.optimizers` instead of the