Update Tokio to Rust 2018 (#1082)

tokio-threadpool/src/thread_pool.rs

@@ -1,11 +1,9 @@
-use builder::Builder;
-use pool::Pool;
-use sender::Sender;
-use shutdown::{Shutdown, ShutdownTrigger};
-
+use crate::builder::Builder;
+use crate::pool::Pool;
+use crate::sender::Sender;
+use crate::shutdown::{Shutdown, ShutdownTrigger};
 use futures::sync::oneshot;
 use futures::{Future, Poll};
-
 use std::sync::Arc;
 
 /// Work-stealing based thread pool for executing futures.
@@ -53,12 +51,9 @@ impl ThreadPool {
     /// # Examples
     ///
     /// ```rust
-    /// # extern crate tokio_threadpool;
-    /// # extern crate futures;
     /// # use tokio_threadpool::ThreadPool;
     /// use futures::future::{Future, lazy};
     ///
-    /// # pub fn main() {
     /// // Create a thread pool with default configuration values
     /// let thread_pool = ThreadPool::new();
     ///
@@ -69,7 +64,6 @@ impl ThreadPool {
     ///
     /// // Gracefully shutdown the threadpool
     /// thread_pool.shutdown().wait().unwrap();
-    /// # }
     /// ```
     ///
     /// # Panics
@@ -93,12 +87,9 @@ impl ThreadPool {
     /// # Examples
     ///
     /// ```rust
-    /// # extern crate tokio_threadpool;
-    /// # extern crate futures;
     /// # use tokio_threadpool::ThreadPool;
     /// use futures::future::{Future, lazy};
     ///
-    /// # pub fn main() {
     /// // Create a thread pool with default configuration values
     /// let thread_pool = ThreadPool::new();
     ///
@@ -109,7 +100,6 @@ impl ThreadPool {
     ///
     /// // Gracefully shutdown the threadpool
     /// thread_pool.shutdown().wait().unwrap();
-    /// # }
     /// ```
     ///
     /// # Panics