add conf app and related test and settings

announcement/urls/admin.py

@@ -3,5 +3,5 @@ from django.conf.urls import url
 from ..views import AnnouncementAdminAPI
 
 urlpatterns = [
-    url(r'^$', AnnouncementAdminAPI.as_view(), name="announcement_admin_api"),
+    url(r'^announcement$', AnnouncementAdminAPI.as_view(), name="announcement_admin_api"),
 ]