Fix regression when mounting volumes

Caused by
docker/docker-py@77fec67

Author: aanand

fig/service.py

@@ -222,7 +222,10 @@ def start_container(self, container=None, volumes_from=None, **override_options)
             for volume in options['volumes']:
                 if ':' in volume:
                     external_dir, internal_dir = volume.split(':')
-                    volume_bindings[os.path.abspath(external_dir)] = internal_dir
+                    volume_bindings[os.path.abspath(external_dir)] = {
+                        'bind': internal_dir,
+                        'ro': False,
+                    }
 
         privileged = options.get('privileged', False)
 

tests/service_test.py

@@ -114,6 +114,12 @@ def test_create_container_with_unspecified_volume(self):
         service.start_container(container)
         self.assertIn('/var/db', container.inspect()['Volumes'])
 
+    def test_create_container_with_specified_volume(self):
+        service = self.create_service('db', volumes=['/tmp:/host-tmp'])
+        container = service.create_container()
+        service.start_container(container)
+        self.assertIn('/host-tmp', container.inspect()['Volumes'])
+
     def test_recreate_containers(self):
         service = self.create_service(
             'db',