Switch to the 2018 edition; fix some warnings

Cargo.toml

@@ -2,10 +2,11 @@
 name = "music-sync"
 version = "0.1.0"
 authors = ["Paul van Tilburg <paul@luon.net>"]
+edition = "2018"
 
 [dependencies]
 clap = "2.32.0"
 cursive = "0.9.0"
 failure = "0.1.2"
 lazy_static = "1"
-walkdir = "2"
+walkdir = "2"

src/main.rs

@@ -1,18 +1,9 @@
-#![allow(unknown_lints)]
-#![warn(clippy)]
-
-extern crate clap;
-extern crate cursive;
-extern crate failure;
-#[macro_use]
-extern crate lazy_static;
-extern crate walkdir;
-
 use clap::{App, Arg};
 use cursive::traits::*;
 use cursive::views::{Checkbox, Dialog, ListView, ProgressBar, TextView};
 use cursive::Cursive;
 use failure::Error;
+use lazy_static::lazy_static;
 use std::ffi::OsStr;
 use std::os::unix::process::CommandExt;
 use std::path::PathBuf;
@@ -97,7 +88,7 @@ fn select_albums(ui: &mut Cursive) {
                 let album_name = album_name(&album_path);
                 let album_path = album_path.clone();
 
-                let mut checkbox = Checkbox::new().on_change(move |_, checked| {
+                let checkbox = Checkbox::new().on_change(move |_, checked| {
                     let mut registry = REGISTRY.lock().unwrap();
                     registry.select_album(&album_path, checked);
                 });

src/registry.rs

@@ -50,7 +50,7 @@ impl Registry {
         let line_filter = |line: &&str| line.ends_with("***");
 
         for line in contents.lines().filter(line_filter) {
-            let path = line.trim_left_matches('#').trim_right_matches("/***");
+            let path = line.trim_start_matches('#').trim_end_matches("/***");
             if !line.starts_with('#') {
                 self.selected_albums.insert(PathBuf::from(path));
             }