test v0.12.0.rc0
DO NOT MERGE.
Only to test the CI.

cc @lhoestq @albertvillanova 
_The documentation is not available anymore as the PR was closed or merged._ @Wauplin I was testing it in a dedicated branch without opening a PR: https://github.com/huggingface/datasets/commits/test-hfh-0.12.0rc0 Oops, sorry @albertvillanova. I thought for next time I'll start the CIs before pinging everyone.
I'm closing this one. @Wauplin in your Slack message, you asked people from every major dependent library to check that our CI work. That is why I am checking it... :)

Also, I think for this purpose it is better to test it in a dedicated branch, rather than opening and closing a PR. Yes, yes I know. Completely my fault on this one