github plugin doesn't handle wrong password gracefully

[aspiers]

Failed plugin github:gh: string indices must be integers!
Traceback (most recent call last):
  File "/home/adam/.GIT/3rd-party/rapport/rapport/report.py", line 91, in create_report
    result = future.result()
  File "/usr/lib/python2.7/site-packages/concurrent/futures/_base.py", line 397, in result
    return self.__get_result()
  File "/usr/lib/python2.7/site-packages/concurrent/futures/_base.py", line 356, in __get_result
    raise self._exception
TypeError: string indices must be integers