Release of ureq 3.0.0

ureq 3.0.0 is released replacing the 2.x branch (which is still maintained).

3.x is a ground up rewrite with underpinnings of Sans-IO and retains #![forbid(unsafe_code)]. The library keeps most of the functionality of 2.x, but pivots to use the common http crate as basis for the API.

The goals for ureq remain largely the same: A simple, sync, HTTP/1.1 client with a minimum number of dependencies.

Transport and Resolver are now pluggable, meaning it's possible to use alternative socket implementations, TLS or name resolvers separate to the main project.

Happy to answer any questions.