title: gulp-imagemin jpegtran-bin does not work when I run the simple task
body: <p>I want to compress the images and pipe to the directory of build, but the build folder is empty after running the task. This is my task:</p>
  
  <pre><code>// Gulp.js configuration
  // modules
  const gulp = require('gulp')
  const newer = require('gulp-newer')
  const imagemin = require('gulp-imagemin')
  
  // development mode?
  // let devBuild = (process.env.NODE_ENV !== 'production')
  
  // folders
  const folder = {
    src: 'src/',
    build: 'build/'
  }
  
  gulp.task('images', function () {
    var out = folder.build + 'images/'
    return gulp.src(folder.src + 'images/**/*')
                .pipe(newer(out))
                .pipe(imagemin({optimizationLevel: 5}))
                .pipe(gulp.dest(out))
  })
  </code></pre>
  
  <p>I got the error when I tried to running <code>gulp images</code> and can not found <code>/node_modules/jpegtran-bin/vendor/jpegtran</code> in the <code>node_modules</code></p>
  
  <pre><code>[10:07:18] Using gulpfile ~/Desktop/MyProjects/project1/gulpfile.js
  [10:07:18] Starting 'images'...
  
  events.js:182
        throw er; // Unhandled 'error' event
        ^
  Error: spawn /home/toantd/Desktop/MyProjects/project1/node_modules/jpegtran-bin/vendor/jpegtran ENOENT
  at exports._errnoException (util.js:1026:11)
  at Process.ChildProcess._handle.onexit (internal/child_process.js:189:19)
  at onErrorNT (internal/child_process.js:366:16)
  at _combinedTickCallback (internal/process/next_tick.js:102:11)
  at process._tickCallback (internal/process/next_tick.js:161:9)
  </code></pre>
  
  <p>I also tried to fix this issue follow some links:</p>
  
  <p><a href="https://github.com/imagemin/imagemin/issues/154" rel="nofollow noreferrer">Reinstall node modules</a></p>
  
  <p><a href="https://github.com/imagemin/imagemin-jpegtran/issues/12" rel="nofollow noreferrer">Npm rebuild</a></p>
  
  <p>There is my project structure: </p>
  
  <pre><code>.
  ├── build
  │   ├── css
  │   ├── html
  │   ├── images
  │   └── js
  ├── gulpfile.js
  ├── package.json
  ├── src
  │   ├── html
  │   ├── images
  │   │   ├── bg.jpg
  │   │   └── my-logo.png
  │   ├── js
  │   └── scss
  └── yarn.lock
  </code></pre>
  
  <p>Noted that I'm working under company proxy, but I'm sure that I already set proxy for both of npm and git.</p>
  
  <p>Can anyone help me? Thank you in advance.</p>