Fix readme tests

Related to the change introduced in 6cf47c53.

railties/test/generators/actions_test.rb

@@ -203,14 +203,14 @@ def test_route_should_add_data_to_the_routes_block_in_config_routes
   def test_readme
     run_generator
     Rails::Generators::AppGenerator.expects(:source_root).times(2).returns(destination_root)
-    assert_match(/Welcome to Rails/, action(:readme, "README.rdoc"))
+    assert_match "application up and running", action(:readme, "README.rdoc")
   end
 
   def test_readme_with_quiet
     generator(default_arguments, quiet: true)
     run_generator
     Rails::Generators::AppGenerator.expects(:source_root).times(2).returns(destination_root)
-    assert_no_match(/Welcome to Rails/, action(:readme, "README.rdoc"))
+    assert_no_match "application up and running", action(:readme, "README.rdoc")
   end
 
   def test_log