Bug 1053940 - docker-worker: Encrypted environment variables

One open issue is the management of the gpg keys. Currently they are hard-coded.
as always I'm learning from @jonasfj .  I really like the idea of an incident ID when it comes to security related events.  End user could have a generic error that lets them know that the encrypted payload couldn't be validated, but then debug() could have additional info with the incident ID that someone (I always just recommend @jonasfj ) could go digging into if they wanted to. 

Nice suggestion.