Fix migration

app/views/layouts/nav/_admin.html.haml

@@ -63,7 +63,7 @@
         Background Jobs
   = nav_link(controller: :appearances) do
     = link_to admin_appearances_path, title: 'Appearances' do
-      = icon('image')
+      = icon('image fw')
       %span
         Appearance

db/migrate/20160224201211_change_appearance.rb

 class ChangeAppearance < ActiveRecord::Migration
   def change
+    change_table :appearances do |t|
+      t.remove :dark_logo
+
+      t.rename :light_logo, :header_logo
+    end 
   end
 end