title: What is pipenv [dev-packages] section for?
body: <p>I'm learning <a href="https://pipenv.readthedocs.io/en/latest/" rel="noreferrer">pipenv</a> and there's something I don't quite understand.  Apparently your Pipfile can contain two sections:</p>
  
  <pre><code>[packages]
  ...
  
  [dev-packages]
  ....
  </code></pre>
  
  <p>As I understand it, the packages section is where the packages that you install are listed.  But what is the dev-packages section for?  How is it different from the packages section?</p>