refs https://github.com/TryGhost/Toolbox/issues/332
- After dropping support for `page: (true|false)` for post resources in Content API there is no need to check for `body.post.page` in the AMP renderer. Furthermore, the AMP router uses `public-post` controller that **only** returns "post" resources. This check was a redundant, unnecessary piece of logic
- Some of the helpers inside the routing service would be better suited to their own service
- These two helpers fetchData and entryLookup talk to the API to get data & so make a decent start for a data service
- The data service would be the single point of contact with the API for the frontend
- Doing this now cos I'm moving some files around ahead of deleting things for 5.0
- this is a small part of a bit of cleanup of our test files
- the goal is to make the existing tests clearer with a view to making it easier to write more tests
- this makes the test structure follow the codebase structure more closely
- eventually we will colocate the frontend tests with the frontend code
