resolve ut errors and update changelog version

Author: saimonation

docs/source/UserGuides/Miscellaneous/Changelog.rst

@@ -1,6 +1,14 @@
 Changelog
 =========
 
+2.20.20
+-------
+
+Related issues and pull requests on GitHub: `#316 <https://github.com/ctera/ctera-python-sdk/pull/316>`_,
+`#317 <https://github.com/ctera/ctera-python-sdk/pull/317>`_
+`#318 <https://github.com/ctera/ctera-python-sdk/pull/318>`_
+
+
 Improvements
 ^^^^^^^^^^^^
 

tests/ut/core/admin/test_copy.py

@@ -26,6 +26,7 @@ def test_copy_no_wait(self):
     def _get_expected_copy_params(self, src, dst):
         o = Object()
         o._classname = 'ActionResourcesParam'  # pylint: disable=protected-access
+        o.startFrom = None
         src_dst_obj = Object()
         src_dst_obj._classname = 'SrcDstParam'  # pylint: disable=protected-access
         src_path = self._get_object_path(src)

tests/ut/core/user/base_user.py

@@ -26,6 +26,7 @@ def _create_action_resource_param(self, sources, destinations=None):
         action_resource_param = Object()
         action_resource_param._classname = 'ActionResourcesParam'  # pylint: disable=protected-access
         action_resource_param.urls = []
+        action_resource_param.startFrom = None
         for idx, source in enumerate(sources):
             param = Object()
             param._classname = 'SrcDstParam'  # pylint: disable=protected-access