Issue running in Colab in April 2020

[tkamm]

Just fyi for future users, I got this code running in April 2020 in a colab notebook by reverting to some earlier versions of libraries. I'm not sure what was originally used, so I was guessing based on the original code being from ~March 2019.
!pip install -q torch==1.0.0 torchvision==0.2.0
!pip install pytorch_pretrained_bert==0.5.0

Warning! I don't know if it actually worked as a match to the original experiment since I don't have an exact dataset match.