<filename>tests/urls.py
from django.contrib import admin
#from django.urls import path, include
from django.conf.urls import url, include

urlpatterns = [
    url('admin/', admin.site.urls),
    url('campaign/', include('campaign.urls')),
]

<filename>tests/urls.py
from django.contrib import admin
#from django.urls import path, include
from django.conf.urls import url, include

urlpatterns = [
    url('admin/', admin.site.urls),
    url('campaign/', include('campaign.urls')),
]

#from django.urls import path, include