When describing an action in cli, include the Deckhand revision number

[bryan-strassner]

As per title of issue, when doing a shipyard describe action it would be helpful to show the revision of configuration documents that was used for the action. This will likely require that the Shipyard database be updated with this revision when recording the action (during API POST /actions)

The CLI would need to be updated to show this in the header block of the describe output.

[codebind-luna]

Anyone picked this one?