tests: add head_example_org case

Refs: http-rs#218

tests/test.rs

@@ -4,7 +4,6 @@ use futures_util::future::BoxFuture;
 use http_types::Body;
 
 use surf::{middleware::Next, Client, Request, Response};
-
 #[async_std::test]
 async fn post_json() -> Result<(), http_types::Error> {
     #[derive(serde::Deserialize, serde::Serialize)]
@@ -47,6 +46,20 @@ async fn get_json() -> Result<(), http_types::Error> {
     Ok(())
 }
 
+#[async_std::test]
+async fn head_example_org() -> Result<(), http_types::Error> {
+    let mut res = surf::head("http://example.com").await?;
+
+    assert_eq!(res.status(), surf::StatusCode::Ok);
+    assert!(res.len().is_some());
+
+    let body = res.body_bytes().await?;
+
+    assert_eq!(body.len(), 0);
+
+    Ok(())
+}
+
 #[async_std::test]
 async fn get_google() -> Result<(), http_types::Error> {
     femme::start(log::LevelFilter::Trace).ok();