railsにwebpackを入れたい

Rails & Webpackerでフロントエンド開発環境を整える
こちらの記事に沿って、bin/rake webpacker:installまで手順通りにできたのですが、
その次のbin/webpackを実行しようとすると記事のような出力ではなく、
bundle installを実行した時の出力の後に、次のようなエラーが出力されます。

/home/vagrant/.rbenv/versions/2.4.2/lib/ruby/gems/2.4.0/bundler/gems/webpacker-386fd850a315/lib/webpacker/webpack_runner.rb:11:in `exec': No such file or directory - /vagrant/webpack-sample/node_modules/.bin/webpack (Errno::ENOENT)
	from /home/vagrant/.rbenv/versions/2.4.2/lib/ruby/gems/2.4.0/bundler/gems/webpacker-386fd850a315/lib/webpacker/webpack_runner.rb:11:in `block in run'
	from /home/vagrant/.rbenv/versions/2.4.2/lib/ruby/gems/2.4.0/bundler/gems/webpacker-386fd850a315/lib/webpacker/webpack_runner.rb:10:in `chdir'
	from /home/vagrant/.rbenv/versions/2.4.2/lib/ruby/gems/2.4.0/bundler/gems/webpacker-386fd850a315/lib/webpacker/webpack_runner.rb:10:in `run'
	from /home/vagrant/.rbenv/versions/2.4.2/lib/ruby/gems/2.4.0/bundler/gems/webpacker-386fd850a315/lib/webpacker/runner.rb:6:in `run'
	from /home/vagrant/.rbenv/versions/2.4.2/lib/ruby/gems/2.4.0/bundler/gems/webpacker-386fd850a315/exe/webpack:8:in `<top (required)>'

バージョン

ruby 2.4.2p198
Rails 5.1.4
node v6.10.2

ファイル

/vagrant/

drwxrwxrwx   1 vagrant vagrant    448 2017-11-26 13:12 .
dr-xr-xr-x. 23 root    root      4096 2017-11-26 08:48 ..
-rwxrwxrwx   1 vagrant vagrant   6148 2017-07-05 14:47 .DS_Store
drwxrwxrwx   1 vagrant vagrant     96 2016-12-24 12:56 .vagrant
-rwxrwxrwx   1 vagrant vagrant   3102 2017-11-26 08:45 Vagrantfile
-rwxrwxrwx   1 vagrant vagrant    888 2017-11-21 14:30 gulpfile.js
drwxrwxrwx   1 vagrant vagrant  26272 2017-11-26 13:35 node_modules
-rwxrwxrwx   1 vagrant vagrant 123475 2017-11-26 03:19 package-lock.json
-rwxrwxrwx   1 vagrant vagrant    426 2017-11-26 13:35 package.json
drwxrwxrwx   1 vagrant vagrant    672 2017-11-26 13:18 webpack-sample
-rwxrwxrwx   1 vagrant vagrant 214873 2017-11-26 07:53 yarn.lock

/vagrant/webpack-sample/

drwxrwxrwx 1 vagrant vagrant  672 2017-11-26 13:18 .
drwxrwxrwx 1 vagrant vagrant  448 2017-11-26 13:12 ..
-rwxrwxrwx 1 vagrant vagrant  312 2017-11-26 13:18 .babelrc
drwxrwxrwx 1 vagrant vagrant  416 2017-11-26 13:13 .git
-rwxrwxrwx 1 vagrant vagrant  477 2017-11-26 13:18 .gitignore
-rwxrwxrwx 1 vagrant vagrant   58 2017-11-26 13:18 .postcssrc.yml
-rwxrwxrwx 1 vagrant vagrant 1380 2017-11-26 13:14 Gemfile
-rwxrwxrwx 1 vagrant vagrant 3812 2017-11-26 13:14 Gemfile.lock
-rwxrwxrwx 1 vagrant vagrant  374 2017-11-26 13:10 README.md
-rwxrwxrwx 1 vagrant vagrant  227 2017-11-26 13:10 Rakefile
drwxrwxrwx 1 vagrant vagrant  320 2017-11-26 13:18 app
drwxrwxrwx 1 vagrant vagrant  320 2017-11-26 13:18 bin
drwxrwxrwx 1 vagrant vagrant  480 2017-11-26 13:18 config
-rwxrwxrwx 1 vagrant vagrant  130 2017-11-26 13:10 config.ru
drwxrwxrwx 1 vagrant vagrant   96 2017-11-26 13:10 db
drwxrwxrwx 1 vagrant vagrant  128 2017-11-26 13:10 lib
drwxrwxrwx 1 vagrant vagrant  128 2017-11-26 13:18 log
drwxrwxrwx 1 vagrant vagrant  288 2017-11-26 13:10 public
drwxrwxrwx 1 vagrant vagrant  288 2017-11-26 13:10 test
drwxrwxrwx 1 vagrant vagrant  128 2017-11-26 13:10 tmp
drwxrwxrwx 1 vagrant vagrant   96 2017-11-26 13:10 vendor

確かに、node_module はwebpack-sampleディレクトリ内にはないのですが...
どうしたら良いのでしょうか。
ど初心者のため不備等あるかと思いますが、ご教授お願いいたします。