[RED] Add handler for existing users

apps/accounts/tests/test_units/test_accounts.py

@@ -137,6 +137,22 @@ class AccountViewTest(APITestCase):
             f'"action_type":"{ACTIVITY_TYPE_CREATE}"', response_string
         )
 
+    def test_create_existing_user_fails(self):
+        url = self.BASE_URL
+        data = {
+            "name": self.faker.name(),
+            "username": "user_1",
+            "password": "justpass",
+            "email": self.faker.email(),
+            "phone_number": self.faker.phone_number(),
+            "area": self.faker.city(),
+            "is_admin": False,
+            "is_verified": True,
+            "is_active": True,
+        }
+        response = self.client.post(path=url, data=data, format="json",)
+        self.assertEqual(response.status_code, status.HTTP_409_CONFLICT)
+
     def test_create_new_account_fails_with_poor_password(self):
         url = self.BASE_URL
         _account_id = self.faker.email()