[Checkins] [zopefoundation/cipher.background] c1cfe5: Stop using deprecated --use-mirrors

[GitHub]

  Branch: refs/heads/master
  Home:   https://github.com/zopefoundation/cipher.background
  Commit: c1cfe501422bcdbd169c160088e4f7ab950deb83
      https://github.com/zopefoundation/cipher.background/commit/c1cfe501422bcdbd169c160088e4f7ab950deb83
  Author: Marius Gedminas <marius at gedmin.as>
  Date:   2015-11-08 (Sun, 08 Nov 2015)

  Changed paths:
    M .travis.yml

  Log Message:
  -----------
  Stop using deprecated --use-mirrors