Simplify orchestration adapter client

@alexwelch Decided to go ahead and strip this down to just the basic code we need for this client. I'm still using Faraday so it's similar to our other clients, just without all the ceremony.

Also, added specs.
I think so.  Having to call ```.new```on a module feels odd.  When I call that method, I'm not getting an OrchestrationAdapter instance or even an object with an OrchestrationAdapter ancestor.