Sort list of dashboards by title

Based on feedback, it would be better to have the list of dashboards
sorted by something. Right now I've decided to sort dashboards by
title, but if anyone has a need to change this sort they should
feel free to.
Merge pull request #257 from alphagov/sort-dashboards-by-title

Sort list of dashboards by title
Work in progress - DO NOT MERGE - opening this so it's a bit easier to see the diff and keep a list of things to do.

To do:

Should the module types without a specific schema default to module?
Solihull is very wrong - fix it? Module types are wrong?
Add validation on the validate method - not as part of the api
what does clearer errors mean?
continue with draft3?
axis in options?