title: Unable to run official example
body: <p>I'm trying to run <a href="https://developer.mozilla.org/en-US/Add-ons/WebExtensions/Your_second_WebExtension" rel="nofollow">this</a> example. But it won't run.</p>
  
  <p>I've the latest version 45, along with JPM installed. From the command line if I give <code>"jpm run"</code> it gives couple of errors like <code>name</code> should be in all small letters and no content script specified etc.</p>
  
  <p>How to make it run?</p>
  
  <p>I want some options popup when it's browser icon is clicked. But this part as in package.json is n't working:</p>
  
  <pre><code>  "browser_action": {
      "default_icon": "icons/beasts-32.png",
      "default_title": "Beastify",
      "default_popup": "popup/choose_beast.html"
    },
  </code></pre>