transformers version-up

[j-min]

I noticed that the current ipynb demo is failing when installing packages of requirements.txt on colab with Python 3.10 recently. It seems that tokenizers (==0.9.4) which is paired with transformers==4.2.1 is not compatible with Python 3.10 in Colab.

Since I found that changing python version in colab is not trivial, now I'm considering package version-ups so that people can use VL-T5 with recent transformers versions >= 4.31. This might also address tokenization issue #21 relevant to the recent versions of transformers.

Current todos are:

• update modeling_t5.py
  • T5Stack variable version ups (e.g., use_cache=None -> False / head_mask -> layer_head_mask)
• check tokenization.py
  • add some test cases comparing tokenization outputs from the old 4.2.1 version and 4.31.0