Better test case for issue anymail#361

- shortened testcase payload to minimum required
- renamed method to be more consistant with existing code

tests/test_mailgun_webhooks.py

@@ -630,54 +630,13 @@ def test_clicked_event(self):
  self.assertEqual(event.event_type, "clicked")
  self.assertEqual(event.click_url, "https://example.com/test")
 
- def test_no_delivery_status(self):
+ def test_delivery_status_is_none_event(self):
  raw_event = mailgun_sign_payload(
  {
- "signature": {
- "timestamp": "1534108637",
- "token": "651869375b9df3c98fc15c4889b102119add1235c38fc92824",
- "signature": "...",
- },
  "event-data": {
- "tags": [],
- "timestamp": 1534108637.153125,
- "storage": {
- "url": "https://sw.api.mailgun.net/v3/domains/"
- "example.org/messages/eyJwI...",
- "key": "eyJwI...",
- },
- "recipient-domain": "example.com",
- "id": "hTWCTD81RtiDN-...",
- "campaigns": [],
- "user-variables": {},
- "flags": {
- "is-routed": False,
- "is-authenticated": True,
- "is-system-test": False,
- "is-test-mode": False,
- },
- "log-level": "info",
- "envelope": {
- "sending-ip": "333.123.123.200",
- "sender": "[email protected]",
- "transport": "smtp",
- "targets": "[email protected]",
- },
- "message": {
- "headers": {
- "to": "[email protected]",
- "message-id": "20180812211713.1.DF5966851B4BAA99"
- "@example.org",
- "from": "[email protected]",
- "subject": "Testing",
- },
- "attachments": [],
- "size": 809,
- },
- "recipient": "[email protected]",
  "event": "accepted",
  "delivery-status": None,
- },
+ }
  }
  )
  response = self.client.post(