FEATURE: move stylesheet cache out of the uploads directory

db/migrate/20150505044154_add_stylesheet_cache.rb

@@ -0,0 +1,12 @@
+class AddStylesheetCache < ActiveRecord::Migration
+  def change
+    create_table :stylesheet_cache do |t|
+      t.string :target, null: false
+      t.string :digest, null: false
+      t.text :content, null: false
+      t.timestamps
+    end
+
+    add_index :stylesheet_cache, [:target, :digest], unique: true
+  end
+end