add migration fro #10904

db/migrate/20161130102840_add_conf_to_legends.rb

@@ -0,0 +1,12 @@
+require 'carto/db/migration_helper'
+
+include Carto::Db::MigrationHelper
+
+migration(
+  Proc.new do
+    add_column :legends, :conf, :json, null: false, default: '{}'
+  end,
+  Proc.new do
+    drop_column :legends, :conf
+  end
+)