Missing dependencies while setting up DataPusher

I am trying to set up Datapusher via https://docs.ckan.org/projects/datapusher/en/latest/development.html

Running the last step _python datapusher/main.py deployment/datapusher_settings.py_ in my virtual environment,
I met with multiple issues.
Firstly it was ImportError for ckanserviceprovider.web, which I resolved via pip install ckanserviceprovider
Then there was the ImportError for messytables and slugify, which i pip installed as well.
Currently, I am stuck on the **AttributeError for 'module' object has no attribute 'async'**.

Please help, thank you :)