Hi Andrew,
the Mocha support still exists and works exactly the same. We just haven't gotten around to adding new documentation for it yet.
I've adjusted the link in the blog post to match the new location of the recipe.
Please note that the lab flask icon can now be found on the settings/configuration page along with the development mode toggle. These buttons used to be in different places in ArangoDB 2.x.
Cheers,
Alan