GitLab

1. In python3, dict.iteritems() is gone, change it to dict.items(). And it also doesn't treat zip object as a list, so change zip to list type.
2. Add encoding flag with open function to make it more compatible for Windows/Linux system.
3. For newer tensorflow, it expected int64 without giving a dtype parameter to embedding layer. We give it float32 to solve it.

Move gen_data and gen_vocab to parent directory to prevent import madness in the open-source code. Remove unnecessary bazel dependency and documentation in README.

PiperOrigin-RevId: 186638059

PiperOrigin-RevId: 185783053