title: can't build yeoman angular app
body: <p>I have a problem with building an angular js web app generated with yeoman angular generator. I can run the <code>grunt serve</code>, and it's completely fine. But when I tried to build the app using <code>grunt</code>, I got the following errors.</p>
  
  <pre><code>Running "concurrent:dist" (concurrent) task
  Warning: Running "imagemin:dist" (imagemin) task
  Warning: Error: spawn ENOENT in file app/images/yeoman.png Use --force to continue.
  </code></pre>
  
  <p>The thing is I can build that app (exactly the same app, just copy and paste) on other latop, using same OS, same npm version, same grunt version. </p>
  
  <p>I'm using:</p>
  
  <pre>
  mac osx    - v10.9.5
  npm        - v2.0.2
  grunt-cli  - v0.1.13
  grunt      - v0.4.5
  yeoman     - v1.2.1
  </pre>
  
  <p>Please, help me how to fix that error. thanks</p>