Add test for #search_form_for with array of routes.
Add test for #search_form_for with array of routes.

Follow-up to previous commit 83ce93b to address issue #494.

Mario245/ransack,nagyt234/ransack,roman-franko/ransack,activerecord-hackery/ransack,mariorcardoso/ransack,guilleva/ransack,vaski/ransack,reinteractive/ransack,AndrewSwerlick/ransack,outstand/ransack,laserlemon/ransack,martndemus/ransack,avit/ransack,johan--/ransack,Eric-Guo/ransack