Refernece the Person struct from test harness

lib/koans/08_structs.ex

@@ -5,6 +5,11 @@ defmodule Structs do
     defstruct [:name, :age ]
   end
 
+  koan "structs are defined and named after a module" do
+    person = %Person{}
+    assert person == :__
+  end
+
   koan "you can access the fields of a struct" do
     nobody = %Person{}
     assert nobody.age == :__

test/koans_harness_test.exs

@@ -151,6 +151,7 @@ defmodule KoansHarnessTest do
 
   test "Structs" do
     answers = [
+      %Structs.Person{},
       nil,
       "Joe",
       33,