edx/edx-platform — pull request #4591 by benpatterson (2014-07-29 12:12:57+00:00)
Title: Fix false positive test in cms acceptance

This test was passing in Jenkins, but failing in our Solano runs (and locally on firefox).
This is because it was attaching a file that was not there. This change fixes the test
and makes the attachment method smarter so it will fail if it tries attaching a non-existent
file.