test Controller Category#update
test Controller Category#create
test Controller Category#destroy
 test ProductsController#new
 test ProductsController#new assigns @product
test render edit template Product Controller#edit
test assign @product ProductController#edit
test render show template ProductController#show
test assing @product ProductController#show
test update @product ProductController#update
test create @product ProductController#create
test destroy @product ProductController#destroy