Update widgets.py to fix bug with Django >= 2.0
Update widgets.py to fix bug with Django >= 2.0

Additional widget media files are loaded in another order so it happens that jQuery is not ready when taggit_labels.js is loaded. This change adds jQuery to the list of dependencies like it is done in the original django admin widgets.
bennylope/django-taggit-labels,bennylope/django-taggit-labels