Release 0.21.2

Release 0.21.2

Major Features and Improvements

• Expanded capability for per-key analyzers to analyze larger sets of keys that
  would not fit in memory, by storing the key-value pairs in vocabulary files.
  This is enabled by passing a per_key_filename to tft.count_per_key and
  tft.scale_to_z_score_per_key.
• Added tft.TransformFeaturesLayer and
  tft.TFTransformOutput.transform_features_layers to allow transforming
  features for a TensorFlow Keras model.

Bug Fixes and Other Changes

• tft.apply_buckets_with_interpolation now handles NaN values by imputing with
  the middle of the normalized range.
• Depends on tfx-bsl>=0.21.3,<0.22.

Breaking changes

Deprecations