removed django 3.1 in classifier

Author: agusmakmun

setup.py

@@ -32,7 +32,6 @@ def get_requirements():
         'Framework :: Django :: 2.1',
         'Framework :: Django :: 2.2',
         'Framework :: Django :: 3.0',
-        'Framework :: Django :: 3.1',
         'Intended Audience :: Developers',
         'Operating System :: OS Independent',
         'Programming Language :: JavaScript',