It's very easy to forget to add `require 'rails_helper'` at the top of every core/plugin spec file, and omissions can cause some very confusing/sporadic errors.
By setting this flag in `.rspec`, we can remove the need for `require 'rails_helper'` entirely.
The site settings beginning with "topic views heat" and "topic post like
heat" are set to defaults when installing Discourse, but there has not
been a process or guidance for updating these values based on
community activity.
This feature will update them once a month. The low, medium, and
high settings will be based on the minimums of the 45th, 25th, and
10th percentile topics respectively, so that 45% of topics will have
some "heat".
Disable automatic changes with the automatic_topic_heat_values setting.
