Qi Zhu

It seems that the newest version of `tokenizer` need [rust installed](https://pypi.org/project/tokenizers/). you can install the version we used `tokenizers==0.8.0`. Or install rust.

file to change: - tatk/util - [x] multiwoz/lexicalize.py - [x] multiwoz/state.py - [x] multiwoz/dbquery.py - [x] camrest/lexicalize.py - [x] camrest/state.py - [x] camrest/dbquery.py