Add rustfmt to the tools list

Author: nrc

Cargo.lock

@@ -184,13 +184,13 @@ Studio 2013 and during install select the "C++ tools":
 
 _Install the C++ build tools before proceeding_.
 
-If you will be targetting the GNU ABI or otherwise know what you are
+If you will be targeting the GNU ABI or otherwise know what you are
 doing then it is fine to continue installation without the build
 tools, but otherwise, install the C++ build tools before proceeding.
 "#;
 
 static TOOLS: &'static [&'static str]
-    = &["rustc", "rustdoc", "cargo", "rust-lldb", "rust-gdb", "rls"];
+    = &["rustc", "rustdoc", "cargo", "rust-lldb", "rust-gdb", "rls", "rustfmt"];
 
 static UPDATE_ROOT: &'static str
     = "https://static.rust-lang.org/rustup";

src/rustup-cli/self_update.rs

@@ -16,7 +16,7 @@ pub const LOGMSG_STANDARD: i32 = 2;
 
 // TODO: share this with self_update.rs
 static TOOLS: &'static [&'static str]
-    = &["rustc", "rustdoc", "cargo", "rust-lldb", "rust-gdb", "rls"];
+    = &["rustc", "rustdoc", "cargo", "rust-lldb", "rust-gdb", "rls", "rustfmt"];
 
 #[no_mangle]
 /// This is be run as a `deferred` action after `InstallFiles` on install and upgrade