This folder, lib/travis contains the main code for the Travis Core repository. It contains several sub-section/subdirectories:
addons: Event handlers that take events such as "build finished" and sends out notifications to GitHub, Pusher, Campfire, etc.api: Serializers for models and events used in our API and in some other places (for example to generate Pusher payloads).enqueue: Logic for enqueueing jobs.event: Code for sending and subscribing to events. Used by theaddonscode to subscribe to changes in the models.github: Services for communicating with the GitHub API.mailer: ActionMailer mailers.model: All of our ActiveRecord models.notification: Code for adding instrumentation.requests: Handles requests received from GitHub.secure_config.rb: Logic for encrypting and decrypting build/job configs.services: Most of the business logic behind our API.testing: Code used by our tests, such as model stubs and factories.