Remove six.io. (#285)

There was `six.io` if and only if py3, which was error-prone.

1 files changed, 1 insertions, 0 deletions

diff --git a/six.py b/six.py
index 89b2188..47ecf52 100644
--- a/six.py
+++ b/six.py
@@ -637,6 +637,7 @@ if PY3:
     import io
     StringIO = io.StringIO
     BytesIO = io.BytesIO
+    del io
     _assertCountEqual = "assertCountEqual"
     if sys.version_info[1] <= 1:
         _assertRaisesRegex = "assertRaisesRegexp"