Update demo.py; load() is broken

[chacorp]

for the Colab demo, reinstall pyyaml with !pip install pyyaml==5.4.1 this will fix the error below

TypeError: load() missing 1 required positional argument: 'Loader' in Google Colab

[Zoout]

for the Colab demo, reinstall pyyaml with !pip install pyyaml==5.4.1 this will fix the error below

TypeError: load() missing 1 required positional argument: 'Loader' in Google Colab

solved the problem,thank you!

[graphemecluster]

Hello, I am the author of demo.ipynb. Don't forget to modify requirements.txt:

- PyYAML==5.1
+ PyYAML==6.0