Remove a comment and make spotlight specific stuff clear

As this view also contains generic view stuff I was to make it clear you
can ignore the first bit when you're thinking about this
Test redirect redirects

Add in this test because a preview version of the previous commit should
have caused a test failure - it failed to redirect but this was not
caught
Merge pull request #218 from alphagov/slightly-clearer-spotlight-stuff

Remove a comment and make spotlight specific stuff clear
Add factories for Module and ModuleType
Add support for module ordering

Module order is supported when returning modules in both serialize (for
the admin system) and spotlightify (for the frontend system).

This commit includes adding modules through the /dashboard route but
does NOT include updating existing modules. At the moment this will
raise a NotImplementedError.