refactor all to async/await (#617)

Co-authored-by: Danny Browning <danny.browning@protectwise.com>
Co-authored-by: Daniel Eades <danieleades@hotmail.com>

examples/async.rs

@@ -1,29 +1,16 @@
 #![deny(warnings)]
 
-use futures::{Future, Stream};
-use reqwest::r#async::{Client, Decoder};
-use std::io::{self, Cursor};
-use std::mem;
+use reqwest::r#async::Client;
 
-fn fetch() -> impl Future<Item = (), Error = ()> {
-    Client::new()
-        .get("https://hyper.rs")
-        .send()
-        .and_then(|mut res| {
-            println!("{}", res.status());
+#[tokio::main]
+async fn main() -> Result<(), reqwest::Error> {
+    let mut res = Client::new().get("https://hyper.rs").send().await?;
 
-            let body = mem::replace(res.body_mut(), Decoder::empty());
-            body.concat2()
-        })
-        .map_err(|err| println!("request error: {}", err))
-        .map(|body| {
-            let mut body = Cursor::new(body);
-            let _ = io::copy(&mut body, &mut io::stdout()).map_err(|err| {
-                println!("stdout error: {}", err);
-            });
-        })
-}
-
-fn main() {
-    tokio::run(fetch());
+    println!("Status: {}", res.status());
+
+    let body = res.text().await?;
+
+    println!("Body:\n\n{}", body);
+
+    Ok(())
 }