fix call to resolve_lines_to_highlight on Ruby 2.3
fix call to resolve_lines_to_highlight on Ruby 2.3

mojavelinux/asciidoctor-pdf,Hextremist/asciidoctor-pdf,mojavelinux/asciidoctor-pdf,dsisnero/asciidoctor-pdf,Hextremist/asciidoctor-pdf,dsisnero/asciidoctor-pdf,asciidoctor/asciidoctor-pdf,asciidoctor/asciidoctor-pdf