Managing multiple Rails version with Bundler and rbenv

rails_setup.sh

# make sure homebrew is up to date
brew update
# update ruby version
brew upgrade ruby-build
# install latest stable version
rbenv install 2.3.3
#set version as global
rbenv global 2.3.3
#install bundler for that ruby version
gem install bundler
# create directory
mkdir my-rails-app
# get the latest rails version
gem search rails | grep "^rails "
#add gemfile targetting latest version
echo "source 'https://rubygems.org'" > Gemfile
echo "gem 'rails', '5.0.0.1'" >> Gemfile
#intall Rails version
bundle install
#check that it was installed 
bundle exec rails -v
#create the Rails app (overwrite gemfile)
bundle exec rails new . --force --skip-bundle
bundle update