Fix flake8 test environment

pycodestyle.py

@@ -1689,9 +1689,9 @@ def parse_udiff(diff, patterns=None, parent='.'):
             if path[:2] in ('b/', 'w/', 'i/'):
                 path = path[2:]
             rv[path] = set()
-    return dict([(os.path.join(parent, path), rows)
-                 for (path, rows) in rv.items()
-                 if rows and filename_match(path, patterns)])
+    return dict([(os.path.join(parent, filepath), rows)
+                 for (filepath, rows) in rv.items()
+                 if rows and filename_match(filepath, patterns)])
 def normalize_paths(value, parent=os.curdir):

tox.ini

@@ -5,7 +5,8 @@
 [tox]
 envlist = py26, py27, py32, py33, py34, py35, py36, pypy, pypy3, jython
-skip_missing_interpreters=True
+skipsdist = True
+skip_missing_interpreters = True
 [testenv]
 commands =