Switch from travis to Github Actions

[matthewcarbone]

Just my personal preference. Thoughts?

[zleung9]

It seems "Github Actions" does the same thing as "Circle CI" right? ( I've been using Circle CI set up by Xiaohui.)
"Github Actions" sounds native to Git though, which I personally like. So yeah, it is OK with me : ).

[matthewcarbone]

@zhul9311 I don't think so. Github Actions is native to GitHub as you say. Circle CI is a different service. I like GitHub Actions because it's one less third-party thing we need in the software.