Update package.json for node 12 support
Update package.json for node 12 support

simple node-sass update which fixes this issue
Jean85/reveal.js,rbtcollins/reveal.js,maximesinclair/presentations,lecovi/reveal.js,tehfedaykin/10CommandmentsofCommunityOrganizing,kenkunz/js-crash-course,kenkunz/js-crash-course,siddhartha-gadgil/presentations,lecovi/reveal.js,hakimel/reveal.js,siddhartha-gadgil/presentations,10xEngineer/reveal.js,lvh/reveal.js,dbs/reveal.js,10xEngineer/reveal.js,rbtcollins/reveal.js,lecovi/reveal.js,rbtcollins/reveal.js,seefood/DIYHolidays,jlevallois/Kreveal.js,lvh/reveal.js,rbtcollins/reveal.js,jayramj/agile-retro,rbtcollins/reveal.js,Jean85/reveal.js,maximesinclair/presentations,hakimel/reveal.js,jlevallois/Kreveal.js,tehfedaykin/10CommandmentsofCommunityOrganizing,jayramj/agile-retro,seefood/DIYHolidays,rbtcollins/reveal.js,siddhartha-gadgil/presentations,dbs/reveal.js