[Snyk] Security upgrade html-proofer from 3.7.2 to 3.15.0#42

lyoha1988 wants to merge 1 commit intomasterlyoha1988/github-slideshow:masterfrom

snyk-fix-d56f65814d090a67a36f7e47a34b2a9blyoha1988/github-slideshow:snyk-fix-d56f65814d090a67a36f7e47a34b2a9bCopy head branch name to clipboard