old_contents: from django.conf.urls import url, include
  from django.contrib import admin
  from rest_framework import routers
  from server import views
  
  router = routers.DefaultRouter()
  router.register(r'users', views.UserViewSet)
  router.register(r'groups', views.GroupViewSet)
  
  urlpatterns = [
      url(r'^$', views.index),
      url(r'^api/auth/', include('rest_auth.urls')),
      url(r'^api/', include(router.urls)),
      url(r'^api-auth/', include('rest_framework.urls')),
      url(r'^admin/', admin.site.urls),
  ]
  
new_contents: from django.conf.urls import url, include
  from django.contrib import admin
  from rest_framework import routers
  from server import views
  
  router = routers.DefaultRouter()
  router.register(r'users', views.UserViewSet)
  router.register(r'groups', views.GroupViewSet)
  
  urlpatterns = [
      url(r'^api/auth/', include('rest_auth.urls')),
      url(r'^api/', include(router.urls)),
      url(r'^api-auth/', include('rest_framework.urls')),
      url(r'^admin/', admin.site.urls),
      url(r'^', views.index),
  ]
  
subject: Fix to use react-router for all unmatched routes.