Add pytest-min config

Author: asvetlov

.github/workflows/main.yml

@@ -56,7 +56,6 @@ jobs:
     strategy:
       matrix:
         python-version: ['3.7', '3.8', '3.9', '3.10']
-        pytest-version: [6.1.0, 7.0.0rc1]
 
     steps:
     - uses: actions/checkout@v2

tox.ini

@@ -1,6 +1,6 @@
 [tox]
 minversion = 3.14.0
-envlist = py37, py38, py39, py310, lint, version-info
+envlist = py37, py38, py39, py310, lint, version-info, pytest-min
 skip_missing_interpreters = true
 passenv =
     CI
@@ -11,6 +11,14 @@ commands = make test
 allowlist_externals =
     make
 
+[testenv:pytest-min]
+extras = testing
+deps =
+     pytest == 6.1.0
+commands = make test
+allowlist_externals =
+    make
+
 [testenv:lint]
 skip_install = true
 basepython = python3.9
@@ -37,7 +45,7 @@ commands =
 
 [gh-actions]
 python =
-    3.7: py37
+    3.7: py37, pytest-min
     3.8: py38
     3.9: py39, lint
     3.10: py310