Update to Actix V4

[wyatt-herkamp]

Before you say? BuT tHiS iS nOt IMpOrTaNt

1. Keeping libraries up to date keep things secure
2. I like Rust and it would keep me happy to do this. (Free Dopamine)
3. More Features maybe. IDK

[jaythomas]

At the time of writing, it looks like it's still in RC: https://github.com/actix/actix-web/releases/tag/web-v4.0.0-rc.2

[wyatt-herkamp]

At the time of writing, it looks like it's still in RC: https://github.com/actix/actix-web/releases/tag/web-v4.0.0-rc.2

I know, I have been following this extremely closely. API changes should be finalized.