Fix some cargo fmt complaints

Author: pkgw

src/app_dirs.rs

@@ -1,5 +1,8 @@
-use std::path::PathBuf;
+// Copyright 2019 the Tectonic Project
+// Licensed under the MIT License.
+
 use app_dirs::{AppDataType, AppDirsError};
+use std::path::PathBuf;
 
 pub use app_dirs::sanitized;
 

src/config.rs

@@ -19,10 +19,10 @@ use std::sync::atomic::{AtomicBool, Ordering};
 
 use crate::app_dirs;
 use crate::errors::{ErrorKind, Result};
-use crate::io::Bundle;
 use crate::io::itarbundle::{HttpITarIoFactory, ITarBundle};
 use crate::io::local_cache::LocalCache;
 use crate::io::zipbundle::ZipBundle;
+use crate::io::Bundle;
 use crate::status::StatusBackend;
 
 /// Awesome hack time!!!