My notes on creating a Rails 4.2 app for hosting on Heroku. With RSpec and Postgresql.
# Install RVM, Ruby and Bundler
...
# Install Rails
gem install rails --no-ri --no-rdoc
# Create new app without Test::Unit, and for Postgresql (for Heroku)
rails new MYAPP --skip-test-unit --database=postgresql
# update Gemfile with these gems
gem 'rails_12factor' # for Heroku asset pipeline support, etc
gem 'sqlite3' # add to :development, :test group
gem 'rspec-rails' # add to :test group
bundle install
rails g rspec:install
# create heroku app
heroku apps:create MYAPP
# add heroku Postgresql database
heroku addons:add heroku-postgresql:hobby-dev
# for documentation: `heroku addons:docs heroku-postgresql`
# push to Heroku
git push heroku master
# rake db:migrate
heroku run rake db:migrate