title: Babel - Npm run script with --watch flag
body: <p>So I am wanting to use babel to compile my jsx files on save so the following cli works</p>
  
  <p>babel --presets es2015,react --extensions ".jsx" "ui/app/" --out-dir "ui/app/" --watch</p>
  
  <p>I have babel watch for changes to jsx files and compiles them in place to js files.</p>
  
  <p>Works great.</p>
  
  <p>However if I put that into a npm script block it just hangs and doesn't compile files.</p>
  
  <pre><code>...
  "scripts": {
      "babel-watch": "babel --presets es2015,react --extensions '.jsx' 'ui/app/' --out-dir 'ui/app/' --watch
  }
  ...
  
  Junior@Caldeum MINGW64 ~/Dropbox/SVN/insight_JSPM
  $ npm run babel-watch
  
  &gt; babel --presets es2015,react --extensions ".jsx" "ui/app/" --out-dir "ui/app/" --watch
  
  _
  </code></pre>
  
  <p>Is it possible that I'm missing something here. The command works just fine, but only when ran with npm run it does not.</p>