In regards to needing CI, it appears your project is open sourced. Both Travis [1] and CircleCI [2] both have free tiers for open source projects, worth a look!
[1]: https://travis-ci.com/plans
[2]: https://circleci.com/pricing/
Edit: Add in links
[1]: https://travis-ci.com/plans
[2]: https://circleci.com/pricing/
Edit: Add in links
Additionally, I think we might not scale on the free tier but not sure yet. I tend to use a lot of CI resources. At work I spend about $500 per month on our CI boxes.
> We also offer the Seed plan free (at 1x concurrency) for OS X open source projects.