Adding a failing test on a separate branch to show how pytest error messages...

Adding a failing test on a separate branch to show how pytest error messages are brought up in the gitlab interface. Someone asked me this, I showed him on my fork, but this could be helpful for others as well.

The MR does not allow me to create a branch on your repo. Maybe it is a good idea to keep it as a separate branch to keep a successful main branch 🤔 Up to you.

Thanks for providing this nice simple example 😄