Fix#329.
BREAKING CHANGE: you need to define the proper router in re2o/settings_locals.py for LDAP to continue working properly. See re2o/settings_locals.example.py.
Support for django 2.2. Rename django.conf.urlresolvers. Change url to path. Add apps to app folder. Edit migrations for on_delete. Edit models for on_delete.
Drop compatibility for django 1.x