Expose bytes to the Response object

This patch exposes the `Response::bytes`, which is basically a wrapper
on reqwest::Response::bytes().

Author: laurocaetano

elasticsearch/src/http/response.rs

@@ -21,6 +21,7 @@ use crate::{
     error::Error as ClientError,
     http::{headers::HeaderMap, Method, StatusCode, Url},
 };
+use bytes::Bytes;
 use serde::{
     de,
     de::{DeserializeOwned, MapAccess, Visitor},
@@ -128,6 +129,14 @@ impl Response {
         Ok(body)
     }
 
+    /// Asynchronously reads the response body as bytes
+    ///
+    /// Reading the response body consumes `self`
+    pub async fn bytes(self) -> Result<Bytes, ClientError> {
+        let bytes: Bytes = self.response.bytes().await?;
+        Ok(bytes)
+    }
+
     /// Gets the request URL
     pub fn url(&self) -> &Url {
         self.response.url()