Fix Producer shard range ignoring the last shard

We define the shard range like this in objects
> 'shard': fields.IntegerFields(nullable=True, minimum=0, maximum=4095),

The problem is that in code we handle it using range(0, 4095), but that
range does not include the final shard value of 4095.

Closes-bug: #2044278
Change-Id: I71b0b1b237b5d5f12209f431db19cda1b44a1112
(cherry picked from commit 54d2d2cf18)

designate/producer/service.py

@@ -79,7 +79,7 @@ class Service(service.RPCService):
 
         self._partitioner = coordination.Partitioner(
             self.coordination.coordinator, self.service_name,
-            self.coordination.coordination_id.encode(), range(0, 4095)
+            self.coordination.coordination_id.encode(), range(0, 4096)
         )
 
         self._partitioner.start()

designate/tests/test_producer/test_service.py

@@ -15,13 +15,26 @@
 # under the License.
 from oslo_log import log as logging
 
+from designate import objects
 from designate.tests import TestCase
 
+
 LOG = logging.getLogger(__name__)
 
 
 class ProducerServiceTest(TestCase):
+    def setUp(self):
+        super().setUp()
+        self.producer_service = self.start_service('producer')
+
     def test_stop(self):
-        # Test stopping the service
-        service = self.start_service("producer")
-        service.stop()
+        self.producer_service.stop()
+
+    def test_validate_partition_range(self):
+        self.producer_service.start()
+
+        min_partition = objects.Zone.fields['shard'].min
+        max_partition = objects.Zone.fields['shard'].max
+
+        self.assertIn(min_partition, self.producer_service.partition_range)
+        self.assertIn(max_partition, self.producer_service.partition_range)