Avoid keys order issue by using Maps.has_key?/2

lib/koans/05_maps.ex

@@ -38,7 +38,7 @@ defmodule Maps do
 
   koan "Can remove pairs by key" do
     without_age = Map.delete(@person, :age)
-    assert Enum.sort(Map.keys(without_age)) == ___
+    assert Map.has_key?(without_age, :age) == ___
   end
 
   koan "Can merge maps" do

test/koans/maps_koans_test.exs

@@ -10,7 +10,7 @@ defmodule MapsTests do
       {:ok, "Kayaking"},
       {:ok, 37},
       {:ok, 16},
-      [:last_name, :name],
+      false,
       %{:name => "Jon", :last_name => "Snow"},
       {:ok, "Baratheon"},
       %{ :name => "Jon", :last_name => "Snow"},