update test matrix to the current standards

Author: Thijs Kramer

tox.ini

@@ -1,31 +1,26 @@
 [tox]
 envlist =
-    py{34,35,36}-dj{20}-wt{20,21,22}
-    py{35,36}-dj{21}-wt{23}
-    py{35,36,37}-dj{21}-wt{24}
-    py{35,36,37}-dj{22}-wt{25}
+    py{36,37,38}-dj{22}-wt{27}
+    py{36,37,38}-dj{22,31}-wt{211}
+    py{36,37,38,39}-dj{22,31}-wt{212}
 
 [testenv]
 basepython =
-    py34: python3.4
-    py35: python3.5
     py36: python3.6
     py37: python3.7
+    py38: python3.8
+    py39: python3.9
 
 deps =
     pytest
     pytest-django
     coverage
     codecov
-    dj20: Django>=2.0,<2.1
-    dj21: Django>=2.1,<2.2
     dj22: Django>=2.2,<2.3
-    wt20: wagtail>=2.0,<2.1
-    wt21: wagtail>=2.1,<2.2
-    wt22: wagtail>=2.2,<2.3
-    wt23: wagtail>=2.3,<2.4
-    wt24: wagtail>=2.4,<2.5
-    wt25: wagtail>=2.5,<2.6
+    dj31: Django>=3.1,<3.2
+    wt27: wagtail>=2.7,<2.8
+    wt211: wagtail>=2.11,<2.12
+    wt212: wagtail>=2.12,<2.13
 
 whitelist_externals =
     make