xcode-select --install
Homebrew (https://brew.sh/)
/usr/bin/ruby -e "$(curl -fsSL https://raw.githubusercontent.com/Homebrew/install/master/install)"
Ruby (https://www.ruby-lang.org)
brew update
brew install openssl libyaml libffi rbenv ruby-build
rbenv init
rbenv install 2.3.3
rbenv global 2.3.3
which ruby
which gem
Bundler (http://bundler.io/)
gem install bundler
Postgres (https://www.postgresql.org/)
brew install postgres
brew services start postgresql
Rails (http://rubyonrails.org/)
brew install node@6
gem install rails