message: Use fs::copy instead of copying by hand
diff: @@ -5,7 +5,7 @@ extern crate git2;
  use std::env;
  use std::path::Path;
  -use std::fs::File;
  +use std::fs::{self, File};
  use std::io::Write;
  use git2::Repository;
  @@ -60,8 +60,5 @@ fn copy_js() {
  .expect("open templates/menu.js")
  .read_to_string(&mut javascript)
  .expect("read templates/menu.js");
  - File::create(&dest_path)
  - .expect("create target/.../menu.js")
  - .write_all(javascript.as_bytes())
  - .expect("write target/.../menu.js");
  + fs::copy(&source_path, &dest_path).expect("copy template/menu.js to target");
  }
  