[Outreachy] Setting up development envirenment

Hi Sofia! I have made myself familiar with the launchpad, storyboard and gerrit. I have also experimented in the Sandbox projects. I was trying to set up my development environment following https://docs.openstack.org/cinder/latest/contributor/development.environment... but I was unable to run unit tests, on running command 'tox -e py3' I get error saying AttributeError: module 'py' has no attribute 'io' Kindly help me with this so that I can start working on my first issue :) Thank you!