Add CI and Pub upgrade for this project

[domesticmouse]

This should be a fast follow PR after the initial code lands in #2.

[mit-mit]

Maybe we should land a minimal check for formatting and analysis prior to the code PR?

[domesticmouse]

I've landed CI config into the main branch, but PR #2 doesn't seem to be triggering it.

[domesticmouse]

Closing this out as CI is now landed in main