Port CI to github actions

[schneems]

I am standardizing on GitHub actions for zomboxom for CI as Circle has proven cumbersome. I've ported most of the projects except those that use different versions of Rails.

Help wanted

Also, I'm looking for help maintaining this project in the future. I ask anyone interested to please send a PR and mention that you're interested in helping. You can email me if you've previously had a commit merged in this project.

A maintainer will gain commit access and deploy access on rubygems if they don't have it already. A maintainer will be expected to:

• Update CI to keep tests passing and test new Ruby releases
• Review, merge, or close PRs
• Read and respond to issues
• Any feature or bugfix work that you desire