* `tf.nest` and `tf.data` now support user defined classes implementing `__tf_flatten__` and `__tf_unflatten__` methods. See [nest_util code examples](https://github.com/tensorflow/tensorflow/blob/04869b4e63bfc03cb13627b3e1b879fdd0f69e34/tensorflow/python/util/nest_util.py#L97)
for an example.

*  TensorFlow IO support is now available for Apple Silicon packages.

*  Refactor CpuExecutable to propagate LLVM errors.

  - build: Use go-runner:buster-v2.0.1 (built using go1.15.1)
  - bazel: Replace --features with Starlark build settings flag
  - hack/lib/util.sh: some bash cleanups
    
    - switched one spot to use kube::logging
    - make kube::util::find-binary return an error when it doesn't find
      anything so that hack scripts fail fast instead of with '' binary not
      found errors.