*   Usability improvement: The frequently used tensor filter
        `has_inf_or_nan` is now added to `Session` wrappers and hooks by
        default. So there is no need for clients to call
        `.add_tensor_filter(tf_debug.has_inf_or_nan)` anymore.
*   SinhArcsinh (scalar) distribution added to `contrib.distributions`.
*   Make `GANEstimator` opensource.