PSA: CodeShip just today announced free plans for up to 5 private repositories. Excellent and more than enough for most startups. Get started with CI -today- it's worth it.
Continuous Deployment was also always part of it. Basically we upped from 50 free builds to 100 and announced it properly. But the basic feature set hasn't changed and you currently get all of the features in the free plan that you would get in a larger plan.
https://www.codeship.io/