nature/pa11y — pull request #26 by stephenmathieson (2013-07-17 16:58:13+00:00)
Title: loading invalid configuration files should throw descriptive messages

per [this conversation](https://github.com/nature/pa11y/commit/e08fc3d80cc73c221847570a88aab824a6df81e3#commitcomment-3655399), i'm updating the error message to be more descriptive and easier to debug