Move BlackBox to app/lib (#16183)

.simplecov

@@ -1,18 +1,14 @@
 unless ENV["COVERAGE"] == "false"
   SimpleCov.start "rails" do
     add_filter "/spec/"
-    add_filter "/dashboards/"
     add_filter "/app/controllers/admin/"
-    add_filter "/app/black_box/"
-    add_filter "/app/fields/"
+    add_filter "/app/lib/black_box/"
     add_filter "/app/views/admin/"
 
-    # TODO: [thepracticaldev/oss] enable this when we upgrade to SimpleCov 0.18
-    # enable_coverage :branch
+    enable_coverage :branch
 
     add_group "Decorators", "app/decorators"
     add_group "Errors", "app/errors"
-    add_group "Labor", "app/labor"
     add_group "Liquid tags", "app/liquid_tags"
     add_group "Policies", "app/policies"
     add_group "Queries", "app/queries"

spec/lib/black_box_spec.rb

@@ -1,6 +1,6 @@
 require "rails_helper"
 
-RSpec.describe BlackBox, type: :black_box do
+RSpec.describe BlackBox, type: :lib do
   describe "#article_hotness_score" do
     it "returns higher value for higher score" do
       article = build_stubbed(:article, score: 99, published_at: Time.current)