Do not run migrations from mounted engine separately.

There is no good way now to run migrations for mounted engine in test application,
but that way of running migrations makes it really hard to run
engine in development mode and test it (you need to copy migrations
in dev mode and in that case in tests they will be run twice).
Signed-off-by: NJosé Valim <jose.valim@gmail.com>

railties/lib/rails/generators/rails/plugin_new/templates/test/test_helper.rb

@@ -9,8 +9,6 @@
 <% if full? && !options[:skip_active_record] -%>
 # Run any available migration from application
 ActiveRecord::Migrator.migrate File.expand_path("../dummy/db/migrate/", __FILE__)
-# and from engine
-ActiveRecord::Migrator.migrate File.expand_path("../../db/migrate/", __FILE__)
 <% end -%>
 
 # Load support files