Use correct LaTeX string for conversion tests
Use correct LaTeX string for conversion tests

As of [Pandoc 1.12][1], sections are always labeled. This adds the
section label to the expected string, matching output of Pandoc 1.13.2.

[1]: https://github.com/jgm/pandoc/commit/8d19e45b97d81276b046de2a5078cf5ce0122745

alphabetum/pandoc-ruby,alphabetum/pandoc-ruby,dalehamel/ruby-pandoc