Steps to reproduce the problem
Create or edit a work
In the summary, type in some raw HTML specifying a class, e.g.:
Save the work, then either view the page source or edit it again to see the HTML in the summary field.
Notice that it still containseven though that isn't a valid CSS class
CSS classes starting with a digit, a hyphen, or containing non alphanumeric characters should be stripped out.
This should be as simple as adding to the list in and then removing the corresponding in the test.