FIX proposed for S3io

When I tried running this code, type(outputs[key]) was never == list or == str, so the method, self.s3tolocal, never got called.
When I tried debugging, type(outputs[key]) turned out to be <type 'unicode'>

Author: jason-wg

nipype/interfaces/io.py

@@ -664,6 +664,9 @@ def _list_outputs(self):
                     outputs[key][i] = self.s3tolocal(path, bkt)
             elif type(outputs[key]) == str:
                 outputs[key] = self.s3tolocal(outputs[key], bkt)
+            else:
+                outputs[key] = self.s3tolocal(outputs[key], bkt)
+
 
         return outputs