Check NetworkSettings.Ports instead of HostConfig.PortBindings in tests

The latter appears to be unreliable.

tests/service_test.py

@@ -209,25 +209,25 @@ class ServiceTest(DockerClientTestCase):
     def test_start_container_creates_ports(self):
         service = self.create_service('web', ports=[8000])
         container = service.start_container().inspect()
-        self.assertEqual(list(container['HostConfig']['PortBindings'].keys()), ['8000/tcp'])
-        self.assertNotEqual(container['HostConfig']['PortBindings']['8000/tcp'][0]['HostPort'], '8000')
+        self.assertEqual(list(container['NetworkSettings']['Ports'].keys()), ['8000/tcp'])
+        self.assertNotEqual(container['NetworkSettings']['Ports']['8000/tcp'][0]['HostPort'], '8000')
 
     def test_start_container_creates_port_with_explicit_protocol(self):
         service = self.create_service('web', ports=['8000/udp'])
         container = service.start_container().inspect()
-        self.assertEqual(list(container['HostConfig']['PortBindings'].keys()), ['8000/udp'])
+        self.assertEqual(list(container['NetworkSettings']['Ports'].keys()), ['8000/udp'])
 
     def test_start_container_creates_fixed_external_ports(self):
         service = self.create_service('web', ports=['8000:8000'])
         container = service.start_container().inspect()
-        self.assertIn('8000/tcp', container['HostConfig']['PortBindings'])
-        self.assertEqual(container['HostConfig']['PortBindings']['8000/tcp'][0]['HostPort'], '8000')
+        self.assertIn('8000/tcp', container['NetworkSettings']['Ports'])
+        self.assertEqual(container['NetworkSettings']['Ports']['8000/tcp'][0]['HostPort'], '8000')
 
     def test_start_container_creates_fixed_external_ports_when_it_is_different_to_internal_port(self):
         service = self.create_service('web', ports=['8001:8000'])
         container = service.start_container().inspect()
-        self.assertIn('8000/tcp', container['HostConfig']['PortBindings'])
-        self.assertEqual(container['HostConfig']['PortBindings']['8000/tcp'][0]['HostPort'], '8001')
+        self.assertIn('8000/tcp', container['NetworkSettings']['Ports'])
+        self.assertEqual(container['NetworkSettings']['Ports']['8000/tcp'][0]['HostPort'], '8001')
 
     def test_scale(self):
         service = self.create_service('web')