Merge dev_tmp branch and revert CI changes

[nschcolnicov]

We created a temporary dev branch to work as a dev branch during the holidays and push all of the changes there.
This branch will be reviewed and merged again in january, once everyone is back.
The ci.yml file needs to be updated so that tests now also run for the dev_tmp branch, I added a TODO to remember to revert this change once the branch is merged.
This ticket is created as a reminder of this.
FYI @grst @atrigila @alanmmobbs93 @apeltzer

[nschcolnicov]

Created PR for this: #419 so we don't forget.

Next steps are:

• Reverting changes in ci.yml
• Reviewing changelog.md file