Follow up to: [FEATURE: Create a rake task for destroying categories][1]
- `Discourse.system_user` is my friend
- Remove puts statements from rake tasks that don't return anything
- `for_each` is also my friend
- Use `human_users` to also exclude discobot
- Sort/format categories:list
[1]: 092eeb5ca3
Created a rake task for destroying multiple categories along with any
subcategories and topics the belong to those categories.
Also created a rake task for listing all of your categories.
Refactored existing destroy rake tasks to use new logging method, that
allows for puts output in the console but prevents it from showing in
the specs.
This reduces chances of errors where consumers of strings mutate inputs
and reduces memory usage of the app.
Test suite passes now, but there may be some stuff left, so we will run
a few sites on a branch prior to merging
