Saw the note about GitLab (I work there) and thought I'd chime in.
For those who don't know, we have a GitLab for Open Source program which gives our top tiers and 50K CI minutes/month for free to OSS projects: https://about.gitlab.com/solutions/open-source/
Thanks for chiming in! I like gitlab so much I couldn't miss this opportunity to recommend it.
The nice thing about Gitlab is that you can mix on-prem and saas according to your need.
For example I am now running my own gitlab instance at home but I'm thinking of switching to the gitlab.com offering while keeping runners at home. By pairing gitlab with Hashicorp Vault I could keep encrypted stuff in my repo and decrypt them when they are checked out on the (local on-prem) runner.
For those who don't know, we have a GitLab for Open Source program which gives our top tiers and 50K CI minutes/month for free to OSS projects: https://about.gitlab.com/solutions/open-source/
Hope this helps!