add db migration to remove asset paths from metacodes

db/migrate/20151025083043_remove_asset_paths_from_metacodes.rb

@@ -0,0 +1,8 @@
+class RemoveAssetPathsFromMetacodes < ActiveRecord::Migration
+  def change
+    Metacode.all.each do |metacode|
+      metacode.icon = metacode.icon.gsub(/^\/assets\//, '')
+      metacode.save
+    end
+  end
+end