add bundle install command

.ci/deploy.sh

@@ -16,6 +16,7 @@ for branch in $(git for-each-ref --format='%(refname:strip=3)' refs/remotes); do
     git reset --hard $branch
 
     # build the website
+    bundle install
     bundle exec jekyll build --baseurl="howto-cards/$artefact" -d "public/$artefact"
 
     if [[ $branch == "master" ]]; then