Use def setup instead of setup do

`setup do` creates unnecessary allocations of proc objects in callbacks.
This prevents that from happening and results in faster code.

railties/lib/rails/test_help.rb

@@ -32,13 +32,15 @@ def create_fixtures(*fixture_set_names, &block)
 end
 
 class ActionController::TestCase
-  setup do
+  def setup
     @routes = Rails.application.routes
+    super
   end
 end
 
 class ActionDispatch::IntegrationTest
-  setup do
+  def setup
     @routes = Rails.application.routes
+    super
   end
 end