HTTP/1 and HTTP/2

Starting with v0.3.1, you can configure the HTTP version. If you add Volga like this, HTTP/1 is used by default:

[dependencies]
volga = { version = "..." }

To enable HTTP/2, add the http2 feature or use full:

[dependencies]
volga = { version = "...", features = ["full"] }

With full, HTTP/2 is used when possible, and it falls back to HTTP/1 automatically.