Split genserver koans back up

lib/koans/18_genservers.ex

@@ -134,9 +134,15 @@ defmodule GenServers do
   end
 
   koan "Our server works but it's pretty ugly to use; so lets use a cleaner interface" do
-    Laptop.start_link("EL!73")
-
+    Laptop.start("EL!73")
     assert Laptop.unlock("EL!73") == ___
+  end
+
+  koan "Let's use the remaining functions in the external API" do
+    Laptop.start("EL!73")
+
+    {_, response} = Laptop.unlock("EL!73")
+    assert response == ___
 
     Laptop.change_password("EL!73", "Elixir")