Simplify Django version selection in tox

Author: Kevin Michel

tox.ini

@@ -1,9 +1,7 @@
 [tox]
 envlist =
-    py{27,34,35,36,37,38}-django1
+    py{27,34,35,36,37,38}
     py{35,36,37,38}-aiohttp2
-    py{35,36,37,38}-django2
-    py{36,37,38}-django3
     coverage-report
 
 skip_missing_interpreters = True
@@ -21,9 +19,7 @@ deps =
     Flask-SQLAlchemy
     future
     # the sdk doesn't support earlier version of django
-    py{27,34}-!django2-!django3,django1: django >= 1.10, <2.0
-    py{35}-!django1-!django3,django2: django >= 2.2, <2.3
-    py{36,37,38}-!django1-!django2,django3: django >= 3.0, <4.0
+    django >= 1.10
     django-fake-model
     pynamodb >= 3.3.1
     psycopg2