Update Edge DNS tests and fixtures for NULL SRV records

Thanks to @jdgri for assisting with API tests to confirm support

tests/fixtures/edgedns-records.json

@@ -9,6 +9,22 @@
             "name": "_srv._tcp.unit.tests",
             "ttl": 600
         },
+        {
+            "rdata": [
+                "0 0 0 ."
+            ],
+            "type": "SRV",
+            "name": "_imap._tcp.unit.tests",
+            "ttl": 600
+        },
+        {
+            "rdata": [
+                "0 0 0 ."
+            ],
+            "type": "SRV",
+            "name": "_pop3._tcp.unit.tests",
+            "ttl": 600
+        },
         {
             "rdata": [
                 "2601:644:500:e210:62f8:1dff:feb8:947a"
@@ -151,7 +167,7 @@
         }
     ],
     "metadata": {
-        "totalElements": 16,
+        "totalElements": 18,
         "showAll": true
     }
-}
+}

tests/test_octodns_provider_edgedns.py

@@ -77,14 +77,14 @@ class TestEdgeDnsProvider(TestCase):
 
             zone = Zone('unit.tests.', [])
             provider.populate(zone)
-            self.assertEquals(16, len(zone.records))
+            self.assertEquals(18, len(zone.records))
             changes = self.expected.changes(zone, provider)
             self.assertEquals(0, len(changes))
 
         # 2nd populate makes no network calls/all from cache
         again = Zone('unit.tests.', [])
         provider.populate(again)
-        self.assertEquals(16, len(again.records))
+        self.assertEquals(18, len(again.records))
 
         # bust the cache
         del provider._zone_records[zone.name]
@@ -105,7 +105,7 @@ class TestEdgeDnsProvider(TestCase):
             mock.delete(ANY, status_code=204)
 
             changes = provider.apply(plan)
-            self.assertEquals(29, changes)
+            self.assertEquals(31, changes)
 
         # Test against a zone that doesn't exist yet
         with requests_mock() as mock:
@@ -118,7 +118,7 @@ class TestEdgeDnsProvider(TestCase):
             mock.delete(ANY, status_code=204)
 
             changes = provider.apply(plan)
-            self.assertEquals(14, changes)
+            self.assertEquals(16, changes)
 
         # Test against a zone that doesn't exist yet, but gid not provided
         with requests_mock() as mock:
@@ -132,7 +132,7 @@ class TestEdgeDnsProvider(TestCase):
             mock.delete(ANY, status_code=204)
 
             changes = provider.apply(plan)
-            self.assertEquals(14, changes)
+            self.assertEquals(16, changes)
 
         # Test against a zone that doesn't exist, but cid not provided