cibuild in jekyll-sitemap-1.2.0

- old
+ new

@@ -1,8 +1,5 @@
 #!/bin/sh
 set -e
 
-bundle exec rspec
-bundle exec rspec spec/test_jekyll-last-modified-at.rb
-if [ "$JEKYLL_VERSION" = "3.0" ]; then
-  bundle exec rubocop -S -D
-fi
+time script/fmt
+time script/test