makes the to range method work with or without parentheses
makes the to range method work with or without parentheses

solidusio-contrib/solidus_volume_pricing,spree-contrib/spree_volume_pricing,jspizziri/spree_volume_pricing,spree-contrib/spree_volume_pricing,spree-contrib/spree_volume_pricing,jspizziri/spree_volume_pricing,jspizziri/spree_volume_pricing,solidusio-contrib/solidus_volume_pricing,solidusio-contrib/solidus_volume_pricing,solidusio-contrib/solidus_volume_pricing