With this patch, users could do the following:
mistral exeuction-create wf -d my_first_executio
mistral execution-update d8922ca3-7908-4267-af03-bfad3d95fae2 -d
my_second_execution
However, state and description can't be updated at the same time, since
there is no such scenario and avoid the implementation complexity.
Add some tests accordingly.
Change-Id: Ie10339e5da486a4e2a3e5d31557016be8b3f4fc6
Implements: blueprint workflow-execution-description-support
66b3faabc0