title: Django rest auth email instead of username
body: <p>I have a django project in which I am using Django-rest-auth to do authentication. I want to use <strong><em>email with password</em></strong> to authenticate the user and not the username+password.</p>
  
  <p>I have following settings in my settings.py but it didn't do anything for me:</p>
  
  <pre><code>REST_SESSION_LOGIN = True
  EMAIL_BACKEND = 'django.core.mail.backends.console.EmailBackend'
  ACCOUNT_EMAIL_REQUIRED = True
  ACCOUNT_AUTHENTICATION_METHOD = 'EMAIL'
  ACCOUNT_EMAIL_VERIFICATION = 'optional'
  </code></pre>
  
  <p>How can I achieve it?</p>