Upgrade to tokio 0.3

[mikeyhew]

Tokio 0.3 came out in mid-october (https://tokio.rs/blog/2020-10-tokio-0-3), and they're now on 0.3.3, so it seems like it should be stable enough to upgrade to now. I haven't done an upgrade from 0.2 - 0.3, but just speculating, it looks like the main thing to do is use the new feature flag names, and call the .compat() method from tokio-compat-02 to wrap futures from crates that are still on 0.2.

[seanpianka]

Can you open a PR with the modified Cargo.toml? We can see what fails during compilation then.

[mikeyhew]

It looks like I'm a bit early, hyper just updated to tokio 0.3, but it won't be released until hyper 0.14 is out.

[davepacheco]

I think that link was supposed to be to 2319. I also found 2352, in which the hyper authors explain that the plan will be to release 0.14 when tokio 1.0 is out. Given that, I think the most sensible thing for us is to wait for both of those and then update Dropshot to the newer tokio and hyper.

[mikeyhew]

Thanks! I updated the link. That sounds reasonable, I don't know of any tokio 0.3 features that I'm dying to have, so it's not really worth upgrading until the hyper release comes out

[davepacheco]

It looks like tokio 1.0 and hyper 0.14 were released today.