Bump html-proofer from 5.1.0 to 5.1.1#404

dependabot[bot] wants to merge 1 commit intomainscala/scala.epfl.ch:mainfrom

dependabot/bundler/html-proofer-5.1.1scala/scala.epfl.ch:dependabot/bundler/html-proofer-5.1.1Copy head branch name to clipboard