Solve PyDatalab Incompatible with Python 3.7

!git clone https://github.com/googledatalab/pydatalab.git

!grep -r 'async' --include='*.py' pydatalab/datalab/

!pip install --upgrade requests grpcio
!cd pydatalab && pip install .

!grep -r 'async' --include='*.py' /home/sheng_wei/anaconda3/lib/python3.7/site-packages/datalab/

!grep -r 'yaml' --include='*.py' /home/sheng_wei/anaconda3/lib/python3.7/site-packages/google/datalab/utils/commands/_utils.py