Change some uses of cStringIO.StringIO to io.StringIO.
This is undoubtedly insufficient and in some cases just as broken as before.
diff --git a/Lib/shlex.py b/Lib/shlex.py
index 520b637..964046d 100644
--- a/Lib/shlex.py
+++ b/Lib/shlex.py
@@ -11,10 +11,7 @@
 import sys
 from collections import deque
 
-try:
-    from cStringIO import StringIO
-except ImportError:
-    from StringIO import StringIO
+from io import StringIO
 
 __all__ = ["shlex", "split"]