Fix a pep8 error in tempest/tests2skip.py

Fixes this error when running tox -epep8:

  tempest/tests2skip.py:71:1: W391 blank line at end of file

Change-Id: I150bec112f6db7d80cd55f08eb82d92d8e9a74f3
Merge "Fix a pep8 error in tempest/tests2skip.py"