v2.15.0

Release 2.15.0

Bug Fixes and Other Changes

• Update TF versions and scripts to allow consistently building against tf-nightly.
• No public description
• Update phrase tokenizer to handle end-punctuation.
• Remove private Keras imports.
• Update tensorflow_hub dependency.
• Sprawling .pyi updates related to pybind11 PRs #4831, #4833.
• Report unsupported tensor type in RaggedTensorToTensor in Prepare.
• Check in generated pyi files for some py_extension targets.
• Update version
• Update WORKSPACE