try also 39

setup.cfg

@@ -132,13 +132,14 @@ junit_family = xunit2
 minversion = 3.7
 skip_missing_interpreters = true
 envlist = 
-	py{38}
+	py{38,39}
 recreate = true
 usedevelop = true
 
 [gh-actions]
 python = 
 	3.8: py38
+	3.9: py39
 
 [testenv]
 description = run test suite under {basepython}