v1.0.0-beta1

Major updates:

• Include data necessary for normalize & case folding ops.

Minor updates:

• Update unit tests to work with Python3.
• Fix some wordpiece corner case bugs.
• Wordpiece efficiency improvements.
• Add missing shape_fn to Wordpiece's tokenizeWithOffsets.

v1.0.0-beta0

Initial prerelease for TF.Text library.