You can use application templates to automate these common tasks you do each time you're creating a new Rails application.
Create a new app using the full template:
rails new myapp -m full.rb
Or apply a template to an existing app:
rake rails:template LOCATION=./testing.rb
- full.rb: This will create and configure an application with PostgreSQL, RSpec, Capybara, factory_girls, shoulda-matchers & Thin.
- testing.rb: This will just install and configure RSpec, Capybara, factory_girls & shoulda-matchers.
Point at http://guides.rubyonrails.org/generators.html#application-templates for more info on writing your own templates.