Colab Notebook breaks when downloading the squad dataset
This trick from @thomwolf seems to be the most reliable solution to fix this colab notebook issue:

```python
# install nlp
!pip install -qq nlp==0.2.0

# Make sure that we have a recent version of pyarrow in the session before we continue - otherwise reboot Colab to activate it
import pyarrow
if int(pyarrow.__version__.split('.')[1]) < 16:
    import os
    os.kill(os.getpid(), 9)
```
When I run the notebook in Colab
https://colab.research.google.com/github/huggingface/nlp/blob/master/notebooks/Overview.ipynb
breaks when running this cell:
![image](https://user-images.githubusercontent.com/338917/83311709-ffd1b800-a1dd-11ea-8394-3a87df0d7f8b.png)

Colab Notebook breaks when downloading the squad dataset 
 When I run the notebook in Colab
https://colab.research.google.com/github/huggingface/nlp/blob/master/notebooks/Overview.ipynb
breaks when running this cell:
![image](https://user-images.githubusercontent.com/338917/83311709-ffd1b800-a1dd-11ea-8394-3a87df0d7f8b.png)
 
 This trick from @thomwolf seems to be the most reliable solution to fix this colab notebook issue:

```python
# install nlp
!pip install -qq nlp==0.2.0

# Make sure that we have a recent version of pyarrow in the session before we continue - otherwise reboot Colab to activate it
import pyarrow
if int(pyarrow.__version__.split('.')[1]) < 16:
    import os
    os.kill(os.getpid(), 9)
```