refs: https://github.com/TryGhost/Toolbox/issues/168
- Having large theme fixtures makes tests run slower, so we're working to reduce them
- This fixture was a full copy of a very old version of Casper, but all we needed was a handful of files so that the tests can run
- This theme is also used for testing members, not just price data so I've renamed it for clarity
- The remaining files is the bare minimum we need to test these features
