Replace Travis CI with GHA

[JohnTitor]

On the rust-lang org, we've deprecated the use of Travis CI and migrated to GHA, this PR does it for this repo.
Tested the gh-pages works fine on my fork: https://johntitor.github.io/types-team/
Note that I don't use the scripts on simpleinfra to deploy the gh-pages, as it's outdated and not recommended to use (I remember Pietro said it before, but cannot find the comment on GitHub...)

[nikomatsakis]

r? @rust-lang/infra

[Mark-Simulacrum]

Hm, did we repurpose a repo or something? Where did the Travis file come from - is there a template that needs adjusting?

[jackh726]

@Mark-Simulacrum This repo got renamed wg-traits->types-team

[JohnTitor]

Hm, did we repurpose a repo or something? Where did the Travis file come from - is there a template that needs adjusting?

Looking at 2c992ae, the reason would be "we weren't ready to use GHA (or GHA didn't exist) yet".

[jyn514]

Note that I don't use the scripts on simpleinfra to deploy the gh-pages, as it's outdated and not recommended to use (I remember Pietro said it before, but cannot find the comment on GitHub...)

Can we update those scripts to use the code you have here so people can start using them again? That way we don't have to copy-paste these into each repo.

[JohnTitor]

Can we update those scripts to use the code you have here so people can start using them again? That way we don't have to copy-paste these into each repo.

IIRC the reason that it's not recommended is that action is based on Docker (@pietroalbini Am I correct?): https://github.com/rust-lang/simpleinfra/blob/master/github-actions/static-websites/Dockerfile
It's generally slower than JavaScript's (or other forms of actions) so it isn't straightforward, I guess.

[pietroalbini]

Yeah, the existing Docker action is painfully slow. We should figure out a better solution, but in the meantime the code looks correct!

[JohnTitor]

Could anyone merge this?