The kitchen.text.display module contains code for measuring the width of unicode characters. When the unicode character standard is updated there are new characters introduced that need to be considered by this algorithm. Sometime a new version of python includes an updated list of unicode characters and their width. The failing test is warning us that the list of character sizes in the kitchen module is out of date.
As it stands the module will work exactly the same with python 3.5 or 3.6 The results will be more actuate once the table of unicode characters is updated to match the list included with python 3.6 -- Edward.