Some improvements to the dummy app's User

 * add an ID so it quacks more like an AR object
 * add puts and inspect for debugging

test/dummy_app/app/models/user.rb

@@ -1,14 +1,24 @@
 class User
 
-  attr_reader :name
+  attr_reader :name, :id
 
   def initialize(options = {})
     @name = options[:name]
     @admin = options[:admin]
+    @id = options[:id]
   end
 
   def admin?
     !!@admin
   end
 
+  def to_s
+    name
+  end
+
+  def inspect
+    type = @admin ? 'Admin' : 'User'
+    "<Mock #{type} ##{id}: #{name}>"
+  end
+
 end