I've just set up One Click Orgs on the Travis CI service. This will run our tests automatically when new commits are pushed to GitHub.
It checks both our master and v1.x branches, including both RSpec and Cucumber tests, on both Ruby 1.8.7 and 1.9.2.
You can view the status of the build here:
http://travis-ci.org/#!/oneclickorgs/one-click-orgs
We are currently green!
Chris