`num_tokens`.
        *   `Discretization` added `num_bins` argument for learning bins
            boundaries through calling `adapt` on a dataset. Renamed `bins`
            argument to `bin_boundaries` for specifying bins without `adapt`.
    *   Improvements to model saving/loading:
        *   `model.load_weights` now accepts paths to saved models.

  - 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.
    - this required deleting some genfeddoc stuff. the binary no longer