Update setup.py for new Django and Python versions

Author: ulgens

setup.py

@@ -49,10 +49,13 @@
         "Programming Language :: Python :: 3.6",
         "Programming Language :: Python :: 3.7",
         "Programming Language :: Python :: 3.8",
+        "Programming Language :: Python :: 3.9",
         "Programming Language :: Python :: Implementation :: PyPy",
         "Framework :: Django",
         "Framework :: Django :: 2.2",
         "Framework :: Django :: 3.0",
+        "Framework :: Django :: 3.1",
+        "Framework :: Django :: 3.2",
     ],
     keywords="api graphql protocol rest relay graphene",
     packages=find_packages(exclude=["tests", "examples", "examples.*"]),