title: Enable oauth login with django-allauth but a custom provider
body: <p>I have built an oauth provider using <a href="https://github.com/evonove/django-oauth-toolkit" rel="noreferrer">django-oauth-toolkit</a>.</p>
  
  <p>I would now like to allow users of my client application to log in through this provider.</p>
  
  <p>My understanding is that <a href="https://github.com/pennersr/django-allauth" rel="noreferrer">django-allauth</a> is the ideal tool for this.</p>
  
  <p>I see that django-allauth has a special folder for each provider, and in this folder there is a special files called <code>provider.py</code>. For example, <a href="https://github.com/pennersr/django-allauth/tree/master/allauth/socialaccount/providers/github" rel="noreferrer">this</a> is the folder for the github provider.</p>
  
  <p>Should I be creating something similar to this folder, specially for my custom provider ? Or is there an easier/better way to do this ?</p>