Create a test file for each of the koan modules

test/test_helper.exs

@@ -1 +1,17 @@
 ExUnit.start()
+
+defmodule TestHarness do
+  defmacro __using__(_) do
+    quote do
+      def test_all(module, answers) do
+        module.all_koans
+        |> Enum.zip(answers)
+        |> run_all(module)
+      end
+
+      def run_all(pairs, module) do
+        Enum.map(pairs, fn ({koan, answer}) -> Execute.run_koan(module, koan, [answer]) end)
+      end
+    end
+  end
+end