Fix spec failure related to presence of app config settings. Also, you can't test application controller directly.

app/controllers/application_controller.rb

@@ -57,7 +57,8 @@ class ApplicationController < ActionController::Base
   end
 
   def redirect_unless_admin
-    unless AppConfig[:admins].include?(current_user.username)
+    admins = AppConfig[:admins]
+    unless admins.present? && admins.include?(current_user.username)
       redirect_to root_url
     end
   end

spec/controllers/application_controller_spec.rb

@@ -1,4 +0,0 @@
-require 'spec_helper'
-
-describe ApplicationController do
-end