v0.15.1

Summary

Bug fix patch release.

• Always run tf preprocessing on CPU.
• Fix running preprocessing outside the main python thread.
• Fix loading classifiers with the "old name" of XXClasssifier as XXTextClassifier.
• Restore support for bytestring to tokenizers and other preprocessing layers as strings.

What's Changed

• Version bump for pre-release by @mattdangerw in #1842
• V0.15.1.dev1 by @mattdangerw in #1844
• Version bump for 0.15.1 release by @mattdangerw in #1845

Full Changelog: v0.15.0...v0.15.1