fix #40 - restore tox ini

Author: RonnyPfannschmidt

tox.ini

@@ -0,0 +1,8 @@
+[tox]
+# https://github.com/pytest-dev/apipkg/issues/40
+# this is to support https://src.fedoraproject.org/rpms/pyproject-rpm-macros/blob/rawhide/f/macros.pyproject#_171
+envlist=py37,py38,py39,py310,py311
+isolated_build = True
+[testenv]
+deps=pytest
+commands=pytest []