title: Variable not found. Declare it as envvar or define a default value
body: <p>I am very new to Django and trying to configure <code>python-decouple</code> to use .env variables. I am getting <code>DB_PASSWORD not found. Declare it as envvar or define a default value.</code> when trying to run the server. The .env file is located in the root directory. Here is my code:</p>
  
  <p><strong>settings.py</strong></p>
  
  <pre><code>import os
  from decouple import config
  
  DATABASES = {
      'default': {
          'ENGINE': 'django.db.backends.postgresql',
          'NAME': 'db_development',
          'USER': "db_user",
          'PASSWORD': config('DB_PASSWORD'),
      }
  }
  </code></pre>
  
  <p><strong>my_app.env</strong></p>
  
  <pre><code>DB_PASSWORD=my_password
  </code></pre>