def tag_rename(self, old_tag, new_tag, time=None):
self._add_action('<STR_LIT>')<EOL>return self<EOL>
Rename a tag
See: https://getpocket.com/developer/docs/v3/modify
:param old_tag: old tag name
:param new_tag: new tag name
:param time: time of action
:return: self for chaining
:rtype: Pocket