* In the recent version 2.3.0 of mistral-lib there has been added
the new serialization mechanism for actions since the communication
schema between Mistral engine and Mistral remote executor will soon
require it (once merged). All classes for OpenStack actions are
eventually dynamically generated based on the static classes like
NovaAction, HeatAction etc., so to make the serialization work
correctly we have to take this into account. The newly added class
OpenStackActionSerializer takes care of that.