* set-up for local site-building in ubuntu:
# an alternative is to fork the repo, activate github pages on your
# fork, and test your changes there

: $ sudo apt-get install ruby ruby-dev
# add "~$HOME/.gem/ruby/2.3.0/bin" to your $PATH variable!
: $ gem install --user-install bundle jekyll
: $ echo -e "source 'https://rubygems.org'\ngem 'github-pages', group: :jekyll_plugins" > Gemfile
: $ bundle install --path ~/.gem/ruby/2.3.0/bin
# you may have to install a few dependencies, such as zlib, zlib-dev,
# cmake, etc.
: $ bundle exec jekyll serve
# serves at localhost:4000