Currently the only way to allow tagging on pms is to use the `allow_staff_to_tag_pms` site setting. We are removing that site setting and replacing it with `pm_tags_allowed_for_groups` which will allow for non staff tagging. It will be group based permissions instead of requiring the user to be staff.
If the existing value of `allow_staff_to_tag_pms` is `true` then we include the `staff` groups as a default for `pm_tags_allowed_for_groups`.
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.
