Fix issue #1176: Prevent Django 3 installation

setup.py

@@ -16,7 +16,7 @@ install_requires = [
     'celery>=4.0.2,<4.3.0',
     'celery_once',
 
-    'django>=2.0',
+    'django>=2.0,<3.0',
     'django-bootstrap-form',
     'django-registration==2.4',
     'django-sortedm2m',

tox.ini

@@ -1,7 +1,7 @@
 [tox]
 skipsdist = True
 usedevelop = True
-envlist = py{34,35,36,37}-dj{111,20}
+envlist = py{34,35,36,37}-dj{20}
 
 [testenv]
 setenv =
@@ -11,9 +11,8 @@ basepython =
     py35: python3.5
     py36: python3.6
     py37: python3.7
-deps=
-    dj111: Django>=1.11.1,<2.0
-    dj20: Django>=2.0
+deps=    
+    dj20: Django>=2.0,<3.0
     py37: https://github.com/yaml/pyyaml/zipball/master#egg=pyyaml
     py37: https://github.com/celery/kombu/zipball/master#egg=kombu
 install_command = pip install -e ".[testing]" -U {opts} {packages}