Fixed build error on fedora

Support tf.1.14 and tf.2.0.0

Update setup.py

Remove the LICENSE export as there is no license file in src/

This breaks addlicensedeps.py for AGSA.

PiperOrigin-RevId: 252439316

fixed bug of is_unknown in Python module

Update make_py_wheel_mac.sh

remove control characters in the default nmt_* normalizers

Update VERSION

Merge pull request google#241 from google/sr

load tf versioned so file to avoid abi incompatibility for mac

Merge pull request google#241 from google/sr

load tf versioned so file to avoid abi incompatibility for mac