Benchmark against AI4Thai

[cstorm125]

Benchmark wanchanberta results (all models; see https://arxiv.org/abs/2101.09635) against AI4thai APIs](https://aiforthai.in.th/service_bn.php):

• [x] en-th machine translation
• [ ] zh-th machine translation (pending model from AI Builders)
• [ ] word tokenization (possibly against newmm, deepcut, attacut, sefr)
• [ ] sentiment analysis
• [ ] POS
• [ ] NER
• [ ] Word Similarity (vs our zero-shot model?)
• [ ] Extractive Question Answering