The Optimizely Ruby Library by Martijn Scheijbeler is an unofficial gem that allows developers to integrate the Optimizely API into their Ruby applications.
The latest release of Postman (version 5.0) includes Pro features for free. Now Postman users with free accounts have access, with usage limits, to Pro features such as mock servers, API monitoring, automatic documentation generation and publication, and the Postman Pro API.
While there are numerous API testing solutions, the Ruby Airborne API tester Gem will be of interest to those with a strong inclination towards the Ruby platform. If you follow along all the steps you'll create an API test running against the Trello API, a real API with formal authentication tokens.