Fix rubocop RSpec/DescribedClassModuleWrapping warnings

[denny]

I've decided to move this into the rubocop todo file, as something that should be removed from the code at some point.

I think it's a pretty simple fix, but there are about 30 spec files that need changing so it migth takea while to work through.

Basic instructions:

1. Remove the exception from the todo file.
2. Run rubocop.
3. For each file this cop warns about: a. Remove the module wrapper from the spec file b. Fix any class references in that file that need explicit namespacing after 3a

If anybody wants to pick it up, that'd be great (and I'm happy to help, just get in touch if you want a bit more explanation or even to pair on it), otherwise it can sit in the backlog until I want something simple to sort out :)