[LTP] [PATCH 3/3] CI: Move from Travis to GitHub Actions

[Li Wang]

> > Fixes: https://github.com/linux-test-project/ltp/issues/761
>
> Good work, thanks for doing this, acked.
>
> Also please do not forget to remove the travis user from LTP github repo
> once this is applied.

Btw, seems also need to remove Travis stuff from docs:).

-- 
Regards,
Li Wang