build: remove files, when publish on gh-pages

deploy_ghpages.sh

@@ -25,7 +25,7 @@ rm -Rf gh-pages
 git clone -b gh-pages --single-branch https://${GH_TOKEN}@github.com/${repo} gh-pages
 cd gh-pages
 
-rsync -avz --stats ../build/asciidoc/html5/. .
+rsync -az --stats --delete --force ../build/asciidoc/html5/ .
 
 git config --local user.email "[email protected]"
 git config --local user.name "Travis"