ci: move to github actions

[lovesegfault]

This allows us to use all the nice things from GH actions and actions-rs

[lovesegfault]

Given the discussion in #60 I'll be adding an MSRV check

[parasyte]

Some other things would be really nice to have here:

1. Should allow failures on nightly
2. Perform weekly builds with on.schedule to avoid bitrot.
3. check should run cargo fmt --all -- --check and cargo doc --workspace --no-deps to enforce formatting and docs best practices. (I see fmt is in lints ... might be fine there)
4. lints should run cargo clippy --all --tests -- -D warnings to deny warnings

[lovesegfault]

@parasyte I can't figure out how to allow failures, would you rather have a blocking nightly or no nightly?

[lovesegfault]

Alright, I think I got all other requests done :)

[parasyte]

Hmmm, good question! I guess I would rather remove nightly, sadly. There is https://help.github.com/en/actions/reference/workflow-syntax-for-github-actions#jobsjob_idstepscontinue-on-error but it looks like you will have to create separate checks tests jobs for nightly with this.

[lovesegfault]

Alright, I fixed the syntax errors :)

[lovesegfault]

@parasyte After you merge this, please remember to update the badge in the README, I can't get the correct link until this is merged and the actions window shows up :)

[parasyte]

Thanks! I'll give it a try.