Create model decorator

-----FAILING TEST-----

1) ModelDecorator#uuid adds a Version 5 (SHA-1 hash) UUID
   Failure/Error: subject { ModelDecorator.new(model).response }
   ArgumentError:
     wrong number of arguments (1 for 0)
Add initialize method to ModelDecorator class

-----FAILING TEST-----

1) ModelDecorator#uuid adds a Version 5 (SHA-1 hash) UUID
   Failure/Error: subject { ModelDecorator.new(model).response }
   NoMethodError:
     undefined method `new' for nil:NilClass
Simplyfy failing test

- was trying to dynamically create a class that descends from ActiveRecord::Base
- simplified the approach by simply using a Struct
- nothing in the test had anything to do with ActiceRecord::Base anyway
Add response method to ModelDecorator class

-----FAILING TEST-----

1) ModelDecorator#uuid adds a Version 5 (SHA-1 hash) UUID
   Failure/Error: uuid = subject.uuid
   NoMethodError:
     undefined method `uuid' for nil:NilClass
Add model object to response method in ModelDecorator

-----FAILING TEST-----

1) ModelDecorator#uuid adds a Version 5 (SHA-1 hash) UUID
   Failure/Error: uuid = subject.uuid
   NoMethodError:
     undefined method `uuid' for nil:NilClass
Refactor the uuid method test for ModelDecorator class
Green:  ModelDecorator#uuid adds a Version 5 (SHA-1 hash) UUID

- Test passing.  Woohoo!