Remove unused code and warnings

Author: josevalim

lib/gettext/compiler.ex

@@ -42,8 +42,6 @@ defmodule Gettext.Compiler do
 
     default_domain = opts[:default_domain] || @default_domain
 
-    Module.put_attribute(env.module, :gettext_default_domain, default_domain)
-
     quote do
       @behaviour Gettext.Backend
 

mix.exs

@@ -31,7 +31,7 @@ defmodule Gettext.Mixfile do
 
   def application do
     [
-      applications: [:logger],
+      extra_applications: [:logger],
       env: [default_locale: "en"],
       mod: {Gettext.Application, []}
     ]

test/mix/tasks/gettext.extract_test.exs

@@ -20,7 +20,7 @@ defmodule Mix.Tasks.Gettext.ExtractTest do
       end
 
       def application() do
-        []
+        [extra_applications: [:logger, :gettext]]
       end
     end
     """)