tox: define the minimal tox version required (#5914)

pypa · Oct 24, 2018 · 116c3b1 · 116c3b1
1 parent 951e0cb
commit 116c3b1
Showing 1 changed file with 1 addition and 0 deletions.
diff --git a/tox.ini b/tox.ini
@@ -1,4 +1,5 @@
 [tox]
+minversion = 3.4.0
 envlist =
     docs, packaging, lint-py2, lint-py3, mypy,
     py27, py34, py35, py36, py37, py38, pypy, pypy3