Use boost::to_lower_copy
Use boost::to_lower_copy

NobbZ/xcpp,oalbe/xcpp,daniellehrner/xcpp,NobbZ/xcpp,patricksjackson/xcpp,lukasz-m-maciejewski/xcpp,oalbe/xcpp,exercism/xcpp,exercism/xcpp,lukasz-m-maciejewski/xcpp,patricksjackson/xcpp,daniellehrner/xcpp