chore(lib): add dyn keyword to trait objects (#1820)

Requires Rust 1.27.

src/body/body.rs

@@ -1,4 +1,5 @@
 use std::borrow::Cow;
+use std::error::Error as StdError;
 use std::fmt;
 
 use bytes::Bytes;
@@ -39,7 +40,7 @@ enum Kind {
         content_length: Option<u64>,
         recv: h2::RecvStream,
     },
-    Wrapped(Box<Stream<Item = Chunk, Error = Box<::std::error::Error + Send + Sync>> + Send>),
+    Wrapped(Box<dyn Stream<Item = Chunk, Error = Box<dyn StdError + Send + Sync>> + Send>),
 }
 
 struct Extra {
@@ -141,7 +142,7 @@ impl Body {
     pub fn wrap_stream<S>(stream: S) -> Body
     where
         S: Stream + Send + 'static,
-        S::Error: Into<Box<::std::error::Error + Send + Sync>>,
+        S::Error: Into<Box<dyn StdError + Send + Sync>>,
         Chunk: From<S::Item>,
     {
         let mapped = stream.map(Chunk::from).map_err(Into::into);
@@ -457,13 +458,13 @@ impl From<Chunk> for Body {
 }
 
 impl
-    From<Box<Stream<Item = Chunk, Error = Box<::std::error::Error + Send + Sync>> + Send + 'static>>
+    From<Box<dyn Stream<Item = Chunk, Error = Box<dyn StdError + Send + Sync>> + Send + 'static>>
     for Body
 {
     #[inline]
     fn from(
         stream: Box<
-            Stream<Item = Chunk, Error = Box<::std::error::Error + Send + Sync>> + Send + 'static,
+            dyn Stream<Item = Chunk, Error = Box<dyn StdError + Send + Sync>> + Send + 'static,
         >,
     ) -> Body {
         Body::new(Kind::Wrapped(stream))

src/body/payload.rs

@@ -1,3 +1,5 @@
+use std::error::Error as StdError;
+
 use bytes::Buf;
 use futures::{Async, Poll};
 use http::HeaderMap;
@@ -13,7 +15,7 @@ pub trait Payload: Send + 'static {
     type Data: Buf + Send;
 
     /// The error type of this stream.
-    type Error: Into<Box<::std::error::Error + Send + Sync>>;
+    type Error: Into<Box<dyn StdError + Send + Sync>>;
 
     /// Poll for a `Data` buffer.
     ///