A Django app for private messaging between users with a working custom User model implemented

Based on arneb/django-messages

• Updated to work on Django 2.1.1
• Message.id field changed to uuid4
• Removed features I don't need (email and pinax integration)
• Rewritten URLs to use path() rather than url()
• Added a custom User model
• Case insensitive username checking
• Added an example field to user model (pgp_key) with demo of how it is added to forms and admin
• User and Messaging apps are working properly in the admin panel