refs: https://github.com/TryGhost/DevOps/issues/11
This is a pretty huge commit, but the relevant points are:
* Each importer no longer needs to be passed a set of data, it just gets the data it needs
* Each importer specifies its dependencies, so that the order of import can be determined at runtime using a topological sort
* The main data generator function can just tell each importer to import the data it has
This makes working on the data generator much easier.
Some other benefits are:
* Batched importing, massively speeding up the whole process
* `--tables` to set the exact tables you want to import, and specify the quantity of each
refs: https://github.com/TryGhost/Toolbox/issues/440
New command to generate demo data, creates data for over 20 tables in
Ghost, suitable for testing most features of the dashboard, as well as
making guided product tours using newsletters, tiers, many posts and
tags.
Usage: `yarn start generate-data`
Optionally, keep your existing posts / tags with: `yarn start generate-data --use-existing-tags --use-existing-posts`