Update asciidoctor-epub3 requirement from 1.5.0.alpha.19 to 1.5.1#1646

ben merged 1 commit intomasterprogit/progit2:masterfrom

dependabot/bundler/asciidoctor-epub3-1.5.1progit/progit2:dependabot/bundler/asciidoctor-epub3-1.5.1Copy head branch name to clipboard