run_squad.py not running
## ❓ Questions & Help

When I try to run the script to fine-tune BERT on squad using the code from the examples:

```
python ./examples/run_squad.py \
    --model_type bert \
    --model_name_or_path bert-large-uncased-whole-word-masking \
    --do_train \
    --do_eval \
    --do_lower_case \
    --train_file $SQUAD_DIR/train-v1.1.json \
    --predict_file $SQUAD_DIR/dev-v1.1.json \
    --learning_rate 3e-5 \
    --num_train_epochs 2 \
    --max_seq_length 384 \
    --doc_stride 128 \
    --output_dir ../models/wwm_uncased_finetuned_squad/ \
    --per_gpu_eval_batch_size=3   \
    --per_gpu_train_batch_size=3   \
```
But my terminal just gets stuck on this stage

<img width="518" alt="image" src="https://user-images.githubusercontent.com/8890262/69446607-c39b3780-0d22-11ea-8bea-6135f05640da.png">

When I run the pytests, everything has passed
