tox.ini: test on python 3.11 as well
diff --git a/tox.ini b/tox.ini
index 743826e..f191662 100644
--- a/tox.ini
+++ b/tox.ini
@@ -16,7 +16,7 @@
 # Tox global configuration
 #
 [tox]
-envlist = py{37,38,39,310}-{bst-fixed,bst-master}
+envlist = py{37,38,39,310,311}-{bst-fixed,bst-master}
 skip_missing_interpreters = true
 
 #