The train of the BiDAF can be seen in this colab notebook.(about 20 hours)
https://colab.research.google.com/drive/1Ck1Is5N8CsjPcDHgf26QBKZaK4Wnl1iM
The train of the BERT squad model can be seen in this colab notebook(about 10 hours)
https://colab.research.google.com/drive/12s88gLoaPPMh3TM4L-LjMHNv1huvHX8U