WIP-Tests do not break, but I can't connect to local services.

caching/base.py

@@ -4,10 +4,11 @@
 import logging
 
 import django
+from django.core.exceptions import EmptyResultSet
 from django.core.cache.backends.base import DEFAULT_TIMEOUT
 from django.db import models
 from django.db.models import signals
-from django.db.models.sql import EmptyResultSet, query
+from django.db.models.sql import query
 from django.utils import encoding
 
 from caching import config

caching/invalidation.py

@@ -10,8 +10,9 @@
 from django.core.cache import cache as default_cache
 from django.core.cache import caches
 from django.core.cache.backends.base import InvalidCacheBackendError
-from django.utils import encoding, six, translation
-from django.utils.six.moves.urllib.parse import parse_qsl
+from django.utils import encoding, translation
+import six
+from six.moves.urllib.parse import parse_qsl
 
 from caching import config
 

requirements/base.txt

@@ -8,3 +8,4 @@ flake8
 coverage
 psycopg2
 python-memcached>=1.58
+six

tests/testapp/models.py

@@ -2,7 +2,7 @@
 
 import django
 from django.db import models
-from django.utils import six
+import six
 from caching.base import CachingMixin, CachingManager, cached_method
 
 if six.PY3:

tox.ini

@@ -9,7 +9,8 @@ envlist =
     dj{200}-py{34,35,36,37}
     dj{210}-py{35,36,37}
     dj{220}-py{35,36,37}
-    py{27,37}-flake8
+    dj{310}-py{37,38}
+    py{27,37,38}-flake8
     docs
 
 [testenv]
@@ -19,17 +20,18 @@ basepython =
     py35: python3.5
     py36: python3.6
     py37: python3.7
+    py38: python3.8
 commands = {envpython} run_tests.py --with-coverage
 deps =
     py27: -rrequirements/py2.txt
     py{34,35,36,37}: -rrequirements/py3.txt
     dj111: Django>=1.11,<2.0
     dj200: Django>=2.0,<2.1
     dj210: Django>=2.1,<2.2
-    dj220: Django==2.2b1
+    dj310: Django==3.1
 
 [testenv:docs]
-basepython = python3.7
+basepython = python3.8
 deps =
     Sphinx
     Django
@@ -46,3 +48,7 @@ commands = flake8
 [testenv:py37-flake8]
 deps = flake8
 commands = flake8
+
+[testenv:py38-flake8]
+deps = flake8
+commands = flake8