Fix clippy warnings in warp-key-value-store (#637)

Author: jplatte

examples/warp-key-value-store/src/main.rs

@@ -193,22 +193,22 @@ mod tests {
         let client = reqwest::Client::builder().gzip(true).build().unwrap();
 
         let response = client
-            .get(&format!("http://{}/foo", addr))
+            .get(format!("http://{}/foo", addr))
             .send()
             .await
             .unwrap();
         assert_eq!(response.status(), StatusCode::NOT_FOUND);
 
         let response = client
-            .post(&format!("http://{}/foo", addr))
+            .post(format!("http://{}/foo", addr))
             .body("Hello, World!")
             .send()
             .await
             .unwrap();
         assert_eq!(response.status(), StatusCode::OK);
 
         let response = client
-            .get(&format!("http://{}/foo", addr))
+            .get(format!("http://{}/foo", addr))
             .send()
             .await
             .unwrap();