Changed scaffold generated controller tests to use #to_param.

Before, the generated controller tests were calling #id, which
can change over time, making for brittle tests.

Signed-off-by: Michael Koziarski <michael@koziarski.com>
[#1913 state:committed]

railties/lib/rails_generator/generators/components/scaffold/templates/functional_test.rb

@@ -21,23 +21,23 @@ class <%= controller_class_name %>ControllerTest < ActionController::TestCase
   end
 
   test "should show <%= file_name %>" do
-    get :show, :id => <%= table_name %>(:one).id
+    get :show, :id => <%= table_name %>(:one).to_param
     assert_response :success
   end
 
   test "should get edit" do
-    get :edit, :id => <%= table_name %>(:one).id
+    get :edit, :id => <%= table_name %>(:one).to_param
     assert_response :success
   end
 
   test "should update <%= file_name %>" do
-    put :update, :id => <%= table_name %>(:one).id, :<%= file_name %> => { }
+    put :update, :id => <%= table_name %>(:one).to_param, :<%= file_name %> => { }
     assert_redirected_to <%= file_name %>_path(assigns(:<%= file_name %>))
   end
 
   test "should destroy <%= file_name %>" do
     assert_difference('<%= class_name %>.count', -1) do
-      delete :destroy, :id => <%= table_name %>(:one).id
+      delete :destroy, :id => <%= table_name %>(:one).to_param
     end
 
     assert_redirected_to <%= table_name %>_path