Update tox.ini

Author: stephrdev

.python-version

@@ -1,5 +1,3 @@
-3.7.5
-3.6.6
-3.5.6
-3.4.9
-pypy-5.7.1
+3.8.5
+3.7.8
+3.6.11

tox.ini

@@ -1,34 +1,19 @@
 [tox]
-skipsdist = True
-envlist =
-	{py34,py35,pypy,pypy3}-django18
-	{py34,py35,pypy,pypy3}-django19
-	{py34,py35,pypy,pypy3}-django110
-	{py34,py35,py36,py37,pypy3}-django111
-	{py34,py35,py36,py37,pypy3}-django20
-	{py35,py36,py37,pypy3}-django21
-	{py35,py36,py37,pypy3}-django22
-	{py36,py37,pypy3}-django30
-
-[tox:travis]
-3.4 = py34
-3.5 = py35
-3.6 = py36
-3.7 = py37
-pypy3 = pypy3
+isolated_build = true
+envlist = py{36,37,38}-django{20,21,22,30,31}
 
 [testenv]
-skip_install = True
 setenv = PYTHONPATH={toxinidir}
 deps =
-	.[tests]
-	django18: Django>=1.8,<1.9
-	django19: Django>=1.9,<1.10
-	django110: Django>=1.10,<1.11
-	django111: Django>=1.11,<2.0
 	django20: Django>=2.0,<2.1
 	django21: Django>=2.1,<2.2
 	django22: Django>=2.2,<2.3
 	django30: Django>=3.0,<3.1
+	django31: Django>=3.1,<3.2
+whitelist_externals =
+	poetry
+	sh
+skip_install = true
 commands =
-	py.test --cov
+    sh -c 'poetry export --dev --without-hashes | grep -v "^[dD]jango==" | poetry run pip install --no-deps -r /dev/stdin'
+    poetry run pytest --isort --flake8 --black --cov