Add stub files from webhook app

webhook/admin.py

@@ -0,0 +1,3 @@
+from django.contrib import admin
+
+# Register your models here.

webhook/apps.py

@@ -0,0 +1,5 @@
+from django.apps import AppConfig
+
+
+class WebhookConfig(AppConfig):
+    name = 'webhook'

webhook/models.py

@@ -0,0 +1,3 @@
+from django.db import models
+
+# Create your models here.

webhook/tests.py

@@ -0,0 +1,3 @@
+from django.test import TestCase
+
+# Create your tests here.