Return full task JSON when listing querying tasks

It would be nice to have the full task JSON object in the provisioner, when querying for tasks... This way it's easier to know which AMIs to spin up...

Also, I saw a note on login with persona... I've previously done this in python using flask:
https://github.com/mozilla/telemetry-server/tree/master/analysis/debug-service

Note, I'm tempted to suggest that we implement the server-side in node.js... As this would enable us to reuse the task validation routines in the browser. However, python might provide a prettier and more comprehensible implementation. So that is probably just a crazy idea :)