Uplifts PR script fails with Unicode characters

[justnom]

Description

When running the script/uplift.py script it fails on issues containing Unicode characters.

15:46:06  + python script/uplift.py --uplift-using-pr=8196 --uplift-to=release
15:46:07  [ERROR] Error parsing or error returned from API when looking up pull request "8196":
15:46:07  'ascii' codec can't encode character u'\u2026' in position 69: ordinal not in range(128)

Steps to Reproduce

1. Create a PR with Unicode characters
2. Run python script/uplift.py --uplift-using-pr=123 --uplift-to=release with the PR number replacing 123