Update Tokio to Rust 2018 (#1082)

tokio-fs/src/stdin.rs

@@ -1,6 +1,5 @@
-use tokio_io::AsyncRead;
-
 use std::io::{self, Read, Stdin as StdStdin};
+use tokio_io::AsyncRead;
 
 /// A handle to the standard input stream of a process.
 ///
@@ -33,7 +32,7 @@ pub fn stdin() -> Stdin {
 
 impl Read for Stdin {
     fn read(&mut self, buf: &mut [u8]) -> io::Result<usize> {
-        ::would_block(|| self.std.read(buf))
+        crate::would_block(|| self.std.read(buf))
     }
 }