Non-UTF-8 file name creation command fails with IOError

[jrwdunham]

The new createtransfers.py script fails when calling ./createtransfers.py create-variously-encoded-files with IOError: [Errno 84] Invalid or incomplete multibyte or wide character.

This failure happens on the following platforms:

• Mac OS X 10.13.1 High Sierra with any version of python I tried
• Debian 8.9 (jessie) with Python 2.7.13 (i.e., in the python:2.7 Docker container created by the SS Dockerfile)

This failure does not happen with:

• Ubuntu 16.04 xenial and Python 2.7.12