More CI options

[edhebi]

We probably want to add OSX, and have both x86 and x64.

[Ybalrid]

Travis offer free macOS (that's the name of the OS now btw) builds

[edhebi]

So, github actions are pretty nice, they replace travis, appveyor, and the pages script. I still gotta add macos and different platforms but this is promising. This is still on the todo list but less of a priority I gess.