change migrate for sale_audits

db/migrate/20170403174111_create_sale_audits.rb

@@ -13,7 +13,7 @@ class CreateSaleAudits < ActiveRecord::Migration[5.1]
       t.timestamps
     end
 
-    add_index :sale_audits, :remark, remark: 'remark', type: :longtext
+    add_index :sale_audits, :remark, name: 'remark', type: :fulltext
     add_index :sale_audits, [:sale_id, :action, :action_at]
   end
 end