Update README.md

Author: tonisvain

README.md

@@ -6,6 +6,7 @@
 [![Code style Black](https://img.shields.io/badge/code%20style-black-000000.svg?maxAge=2592000)](https://github.com/ambv/black)
 
 :warning: Note that there are major API changes since version 0.1.1 that have to be taken into account when upgrading!
+:warning: Python 2 and Django 1.11 are no longer supported from version 1.4.0!
 
 # Django rest framework sideloading