Get all system events.  Uses GET to /events/system interface.

        :Returns: (list) Events

def events_system(self):
        """
        Get all system events.  Uses GET to /events/system interface.

        :Returns: (list) Events
        """
        # TODO Add paging to this
        response = self._get(url.events_system)
        self._check_response(response, 200)
        return self._create_response(response).get("events")