Replace Circle CI with GitHub Actions

[jonkoops]

Replaces Circle CI with GitHub Actions, which allows forks to run CI without needing to do additional setup. I needed this for my own purposes, since I wanted to contribute some code, and I figured this might be useful for others as well.

This also bumps all the versions of Node.js to the same ones proposed in #151.

[frederikprijck]

Thanks, but I am going to close this as we have an entire automated release infrastructure set up on top of Circle CI and all of our SDKs and Samples (give or take 90 repositories) run on Circle, sorry for that.

You can see I only recently brought this in on master: #152, still need to get it into this branch as well.

We only recently took ownership of this library, and I wanted to do some housekeeping (hence the beta PR) to set us up for success, which is why we only just now brought in the changes in #152 in this lib.

I can tell we are planning to move everything to Github Actions, but not just yet.

[jonkoops]

No problem, this can always be used for future reference 👍

[frederikprijck]

Definetly, appreciate it @jonkoops !