title: Management command does not show up when installed as third party
body: <p>I am the author of <a href="https://github.com/erayerdin/django-persistent-settings" rel="nofollow noreferrer">django-persistent-settings</a>. I have realized something odd.</p>
  <p>The app has <a href="https://github.com/erayerdin/django-persistent-settings/tree/development/persistent_settings/management" rel="nofollow noreferrer">various management commands</a>. When I do <code>python setup.py --help</code> in django-persistent-settings project, the management commands do show up:</p>
  <pre><code>[persistent_settings]
      delvar
      getvar
      setvar
  </code></pre>
  <p>These commands are <a href="https://github.com/erayerdin/django-persistent-settings/tree/development/project/tests/test_commands" rel="nofollow noreferrer">also tested</a> in the library. However, these commands do not show up when I install it to a project. I wonder why that is.</p>
  <p>I have read <a href="https://docs.djangoproject.com/en/2.2/howto/custom-management-commands/" rel="nofollow noreferrer">the related section of the docs</a> but could not have found a warning, subsection or something alike regarding my problem. I have also checked the source code of some other projects having custom management commands such as <a href="https://github.com/jazzband/django-simple-history" rel="nofollow noreferrer">django-simple-history</a> or <a href="https://github.com/encode/django-rest-framework" rel="nofollow noreferrer">django-rest-framework</a>. They do more or less the same thing.</p>
  <p>Is there maybe something I don't know? An issue I haven't seen but encountered somehow?</p>
  <h1>Reanimating the Unexpected Behavior</h1>
  <p>Make sure Django 2 is installed and create a dummy project.</p>
  <pre class="lang-sh prettyprint-override"><code>django-admin --version
  # django 2.2.12 or something similar
  
  django-admin createproject foo
  cd foo
  virtualenv .venv
  source .venv/bin/activate
  pip install &quot;django&lt;3&quot; django-persistent-settings
  </code></pre>
  <p>Open up <code>foo/settings.py</code> and add it <code>INSTALLED_APPS</code>:</p>
  <pre class="lang-py prettyprint-override"><code>INSTALLED_APPS = [
      # ...
      &quot;persistent_settings&quot;
  ]
  </code></pre>
  <p>List commands:</p>
  <pre><code>python setup.py --help
  </code></pre>
  <p>And the commands do not show up.</p>
  <hr />
  <h1>Environment</h1>
  <ul>
  <li>Python 3.8</li>
  <li>Django 2.2.12</li>
  </ul>