git2-hyper backend

[henry40408]

First step of #623. The crate introduces rustls and hyper and tokio as async runtime.

[mainrs]

Wouldn't it be better to have two new features? One that uses hyper with native tls and one that uses hyper with rustls?

Edit: Ok, I think this PR is just about bringing the backend into the workspace. Is the plan to do a follow-up PR with all the other needed changes?

[alexcrichton]

Thanks for the PR! This seems fine to me but I personally don't really know much about all the pieces involved here. For example I wouldn't be able to help out with bug reports, fix CI, etc. For those reasons could something like this live external to this repository? I'd be fine linking to a git2-hyper repository of course!

[mitchmindtree]

@henry40408 exciting stuff - any follow-up on this? Quite interested for a downstream project that's looking to move away from openssl.

[henry40408]

hi @mitchmindtree, I have opened a repository and prepare to publish on https://crates.io. stay tuned.