LogoutView needs a warning or return from previous code

[macielportugal]

Hello, removing the "permission_classes = (IsAuthenticated,)" section from LogoutView can generate unexpected bugs, perhaps it would be better to leave a warning in the documentation or return the code. In my case I was getting the error "Cannot apply DjangoModelPermissions on a view that does not set .queryset or have a .get_queryset() method." because of my DEFAULT_PERMISSION_CLASSES