Built for Ruby
CircleCI provides support for a wide variety of Ruby versions and gems, including Ruby on Rails. It is trivial to add any packages or frameworks that are not installed on our machines by default, allowing you to effortlessly customize your test enviroment. CircleCI also supports Test::Unit, RSpec, Cucumber, Spinach, Jasmine, Konacha, and just about any other testing framework you use for your Ruby project.
Built-in database support
CircleCI manages all your database requirements for you, such as running your rake commands for creating, loading, and migrating your database. We have pre-installed more than a dozen databases and queues, including PostgreSQL, MySQL, and MongoDB as well as frameworks such as DataMapper, Mongoid, and ActiveRecord. You can also add custom database commands via your circle.yml.