Change format of data sent to api when adding user to service

The endpoint for adding a user to a service in api will now deal with
both user permissions and a user's folder permissions, so this changes
the format of the data we pass through.

app/notify_client/user_api_client.py

@@ -153,7 +153,10 @@ class UserApiClient(NotifyAdminAPIClient):
     def add_user_to_service(self, service_id, user_id, permissions):
         # permissions passed in are the combined admin roles, not db permissions
         endpoint = '/service/{}/users/{}'.format(service_id, user_id)
-        data = [{'permission': x} for x in translate_permissions_from_admin_roles_to_db(permissions)]
+        data = {
+            'permissions': [{'permission': x} for x in translate_permissions_from_admin_roles_to_db(permissions)]
+        }
+
         self.post(endpoint, data=data)
 
     @cache.delete('user-{user_id}')

tests/app/notify_client/test_user_client.py

@@ -154,7 +154,7 @@ def test_client_converts_admin_permissions_to_db_permissions_on_add_to_service(a
 
     user_api_client.add_user_to_service('service_id', 'user_id', permissions={'send_messages', 'view_activity'})
 
-    assert sorted(mock_post.call_args[1]['data'], key=lambda x: x['permission']) == sorted([
+    assert sorted(mock_post.call_args[1]['data']['permissions'], key=lambda x: x['permission']) == sorted([
         {'permission': 'send_texts'},
         {'permission': 'send_emails'},
         {'permission': 'send_letters'},