Fix deprecation warnings for sleep_ms

std::thread::sleep_ms has been deprecated in favor of std::thread::sleep
with a std::time::Duration being passed as the argument. This updates
all usage in this project of sleep_ms with sleep.

rust-install/src/utils/raw.rs

@@ -8,6 +8,7 @@ use std::process::{Command, Stdio, ExitStatus};
 use std::ffi::{OsStr, OsString};
 use std::fmt;
 use std::thread;
+use std::time::Duration;
 use hyper::{self, Client};
 use openssl::crypto::hash::Hasher;
 
@@ -268,7 +269,7 @@ pub fn remove_dir(path: &Path) -> io::Result<()> {
 			if !is_directory(path) {
 				return Ok(());
 			}
-			thread::sleep_ms(100);
+			thread::sleep(Duration::from_millis(100));
 		}
 		result
 	}

src/main.rs

@@ -29,6 +29,7 @@ use std::ffi::OsStr;
 use std::fmt;
 use std::iter;
 use std::thread;
+use std::time::Duration;
 use multirust::*;
 use rust_install::dist;
 use openssl::crypto::hash::{Type, Hasher};
@@ -338,7 +339,7 @@ fn handle_install(cfg: &Cfg, should_move: bool, add_to_path: bool) -> Result<()>
 	if should_move {
 		if cfg!(windows) {
 			// Wait for old version to exit
-			thread::sleep_ms(1000);
+			thread::sleep(Duration::from_millis(1000));
 		}
 		try!(utils::rename_file("multirust", &src_path, &dest_path));
 	} else {