fix wf notebook tests

Until now we used --allow-errors because nbconvert aborts conversion if any cell fails. This fixes it.

mentioned in merge request !398 (merged)

added 6 commits

• 5e70d5f3...8dfd10c9 - 5 commits from branch master
• 2d5b404e - drop --allow-errors from nb tests

Compare with previous version

merged

mentioned in commit 56733b55