[MCC-139310] Feature/moya

Sorry about the mega PR.  I haven't really thought of how swap an app in bite size chunks.  This gets the previous specs working with a new rails app, so it basically implements a simplified index, a show, and a root, as well as the magic for external initializers.  I changed a few things about the drd model.  I changed ``` uuid ``` to ``` id ``` because I always thought "I don't care that its a uuid, its an id that happens to be a uuid".  To this end, I also included ActiveUUID which seemed like a moderately good idea.  I also changed ``` built_at ``` to ``` created_at ``` so we could just use timestamps like normal people.  

A few weird things popped up during this:
1) Crichton has a terrible error if your api descriptors aren't where it is expecting them.  it raises an ``` undefined method transitions on nil ```
2) The ActiveUUID thing started requiring an actual UUID object at some point.  Not sure what I broke.  It should take a string.  Left a todo for a fix.
3) On the index route, I noticed that if you hand crichton a ```{ state: :collection} ``` option it would pass that option on to the drds in ``` items ```, which would explode, because there isn't a state ``` collection ```.  Probably related to the cascading permissions issue.
4) If you hand an ActiveRecord::Relation in instead of an array of instantiated objects, things go boom.

Opened against develop, but I created a branch ``` crichton_test_service ``` that we can keep using until Moya is ready to starburst.

Comments and criticism most welcome.  I'd like us to like this.
@yzhangmedidata @HonoreDB @sheavalentine-mdsol 

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12 examples, 0 failures, 6 pending
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For APIs, apparently, we may want to use :null_session instead.