Basic setup for github actions

[c42f]

I noticed there's no git tags for 0.2.6 or 0.2.7, and that this repo still has a Travis CI setup (likely completely obsolete at this point?)

So I thought it could be helpful to set up TagBot to do release tagging and we may as well have a modern github actions setup for CI as well.

[MasonProtter]

Jeeze @c42f I'm really sorry I never acted on this way back when, I must have forgotten or missed it. Do you have any ideas as to why the CI workflows aren't running?