install bundler version from the Gemfile.lock:
gem install bundler -v 1.15.3 bundle install --path ~/martinus.github.io.bundle
serve it
bundle exec jekyll serve --incremental
faster
bundle exec jekyll serve --watch --limit_posts 1
gem install bundler -v 1.15.3 bundle install --path ~/martinus.github.io.bundle
bundle exec jekyll serve --incremental
bundle exec jekyll serve --watch --limit_posts 1