fix(rustup): update to newest fmt trait names and slice syntax

src/version.rs

@@ -7,7 +7,7 @@ use std::fmt;
 use self::HttpVersion::{Http09, Http10, Http11, Http20};
 
 /// Represents a version of the HTTP spec.
-#[derive(PartialEq, PartialOrd, Copy, Show)]
+#[derive(PartialEq, PartialOrd, Copy, Debug)]
 pub enum HttpVersion {
     /// `HTTP/0.9`
     Http09,
@@ -19,14 +19,14 @@ pub enum HttpVersion {
     Http20
 }
 
-impl fmt::String for HttpVersion {
+impl fmt::Display for HttpVersion {
     fn fmt(&self, fmt: &mut fmt::Formatter) -> fmt::Result {
-        match *self {
+        fmt.write_str(match *self {
             Http09 => "HTTP/0.9",
             Http10 => "HTTP/1.0",
             Http11 => "HTTP/1.1",
             Http20 => "HTTP/2.0",
-        }.fmt(fmt)
+        })
     }
 }