DOC: encoding affects python 2 and 3

Author: wesm

doc/source/io.rst

@@ -94,7 +94,7 @@ data into a DataFrame object. They can take a number of arguments:
   - ``converters``: a dictionary of functions for converting values in certain
     columns, where keys are either integers or column labels
   - ``encoding``: a string representing the encoding to use if the contents are
-    non-ascii, for python versions prior to 3
+    non-ascii
   - ``verbose`` : show number of NA values inserted in non-numeric columns
 
 .. ipython:: python