async-entry

entry macro for tokio based async test.

```rust

[asyncentry::test(init="g()", tracingspan="info")]

async fn foo() { assert!(true); } // Will build a test fn: // #[test] // fn foo() { // let g = g(); // let body = async { // assert!(true); // }; // use tracingfutures::Instrument; // let body = body.instrument(tracing::infospan("foo"); // let rt = tokio::runtime::Builder::newcurrentthread() // .enableall() // .build() // .expect("Failed building the Runtime"); // #[allow(clippy::expectused)] // rt.blockon(body); // }

```