Fix secret_key_base for Railties

This was missed in the security fix for local dev. CI doesn't have a tmp
directory in the apps built for testing so these end up failing. This
adds the secret_key_base so we don't need to generate one.

railties/test/application/url_generation_test.rb

@@ -19,6 +19,7 @@ class MyApp < Rails::Application
         config.session_store :cookie_store, key: "_myapp_session"
         config.active_support.deprecation = :log
         config.eager_load = false
+        config.secret_key_base = "b3c631c314c0bbca50c1b2843150fe33"
       end
 
       Rails.application.initialize!

railties/test/path_generation_test.rb

@@ -65,6 +65,7 @@ def self.name; "ScriptNameTestApp"; end
       def initialize
         super
         app = self
+        app.config.secret_key_base = "b3c631c314c0bbca50c1b2843150fe33"
         @routes = TestSet.new ->(c) { app.controller = c }
         secrets.secret_token = "foo"
       end

railties/test/rails_info_controller_test.rb

@@ -10,6 +10,7 @@ class Base
 
 class InfoControllerTest < ActionController::TestCase
   tests Rails::InfoController
+  Rails.application.config.secret_key_base = "b3c631c314c0bbca50c1b2843150fe33"
 
   def setup
     Rails.application.routes.draw do