Collect all intro printing into display

lib/display.ex

@@ -20,9 +20,15 @@ defmodule Display do
   defp name("Elixir." <> module), do: module
   defp name(module), do: name(Atom.to_string(module))
 
-  def intro(module) do
-    show_intro(module.intro)
-    module
+  def show_failure(failure, module, name) do
+    intro(module, Tracker.visited)
+    IO.puts(format(failure, module, name))
+  end
+
+  defp intro(module, modules) do
+    if ! module in modules do
+      show_intro(module.intro)
+    end
   end
 
   defp show_intro(""), do: nil
@@ -32,9 +38,6 @@ defmodule Display do
     |> IO.puts
   end
 
-  def show_failure(failure, module, name) do
-    IO.puts(format(failure, module, name))
-  end
 
   def format(failure, module, name) do
     """

lib/runner.ex

@@ -40,15 +40,9 @@ defmodule Runner do
   defp track(_, _, _), do: nil
 
   defp display({:failed, error, module, name}) do
-    intro(module, Tracker.summarize)
     Display.show_failure(error, module, name)
     :failed
   end
   defp display(_), do: :passed
 
-  defp intro(module, %{visited_modules: modules}) do
-    if ! module in modules do
-      Display.intro(module)
-    end
-  end
 end

lib/tracker.ex

@@ -19,6 +19,10 @@ defmodule Tracker do
     end)
   end
 
+  def visited do
+    summarize[:visited_modules]
+  end
+
   def complete? do
     %{total: total, current: completed} = summarize
     total == completed