* chore(ci): update CI node version to match node supported versions
* chore(ci): appveyor only supports up to node 16.x
* chore(ci): travis CI is not longer free/working; remove it
* chore(ci): add git workflow to replace travisCI linux builds
* doc(readme): add back in a badge for linux CI
* chore(ci): add windows to CI
* chore(ci): remove appveyor in favor of github actions
* doc(readme): update info about node supportability
