remove unnecessary extern crate lines

src/async_impl/body.rs

@@ -1,6 +1,6 @@
 use std::fmt;
 
-use futures::{Future, Stream, Poll, Async};
+use futures::{Future, Stream, Poll, Async, try_ready};
 use bytes::{Buf, Bytes};
 use hyper::body::Payload;
 use tokio::timer::Delay;

src/async_impl/client.rs

@@ -28,6 +28,8 @@ use mime;
 use native_tls::TlsConnector;
 use tokio::{clock, timer::Delay};
 
+use log::{debug};
+
 
 use super::request::{Request, RequestBuilder};
 use super::response::Response;

src/async_impl/decoder.rs

@@ -31,6 +31,8 @@ use futures::{Async, Future, Poll, Stream};
 use hyper::{HeaderMap};
 use hyper::header::{CONTENT_ENCODING, CONTENT_LENGTH, TRANSFER_ENCODING};
 
+use log::{warn};
+
 use super::{Body, Chunk};
 use crate::error;
 

src/async_impl/response.rs

@@ -5,7 +5,7 @@ use std::net::SocketAddr;
 use std::borrow::Cow;
 
 use encoding_rs::{Encoding, UTF_8};
-use futures::{Async, Future, Poll, Stream};
+use futures::{Async, Future, Poll, Stream, try_ready};
 use futures::stream::Concat2;
 use http;
 use hyper::{HeaderMap, StatusCode, Version};
@@ -16,6 +16,7 @@ use tokio::timer::Delay;
 use serde::de::DeserializeOwned;
 use serde_json;
 use url::Url;
+use log::{debug};
 
 
 use crate::cookie;