Ensure engine migrations are copied in the same sequence that they are required.

activerecord/lib/active_record/railties/databases.rake

@@ -498,7 +498,7 @@ namespace :railties do
     # desc "Copies missing migrations from Railties (e.g. plugins, engines). You can specify Railties to use with FROM=railtie1,railtie2"
     task :migrations => :'db:load_config' do
       to_load = ENV['FROM'].blank? ? :all : ENV['FROM'].split(",").map {|n| n.strip }
-      railties = {}
+      railties = ActiveSupport::OrderedHash.new
       Rails.application.railties.all do |railtie|
         next unless to_load == :all || to_load.include?(railtie.railtie_name)