Add rake to remove deprecated settings

spec/lib/tasks/settings_spec.rb

@@ -1,6 +1,39 @@
 require "rails_helper"
 
-describe "Settings Rake" do
+describe Setting do
+
+  context "Remove deprecated settings" do
+
+    let :run_remove_deprecated_settings_task do
+      Rake::Task["settings:remove_deprecated_settings"].reenable
+      Rake.application.invoke_task "settings:remove_deprecated_settings"
+    end
+
+    before do
+      Setting.create(key: "place_name", value: "City")
+      Setting.create(key: "banner-style.banner-style-one", value: "Style one")
+      Setting.create(key: "banner-style.banner-style-two", value: "Style two")
+      Setting.create(key: "banner-style.banner-style-three", value: "Style three")
+      Setting.create(key: "banner-img.banner-img-one", value: "Image 1")
+      Setting.create(key: "banner-img.banner-img-two", value: "Image 2")
+      Setting.create(key: "banner-img.banner-img-three", value: "Image 3")
+      Setting.create(key: "verification_offices_url", value: "http://offices.url")
+      Setting.create(key: "not_deprecated", value: "Setting not deprecated")
+      run_remove_deprecated_settings_task
+    end
+
+    it "Rake only removes deprecated settings" do
+      expect(Setting.where(key: "place_name").count).to eq(0)
+      expect(Setting.where(key: "banner-style.banner-style-one").count).to eq(0)
+      expect(Setting.where(key: "banner-style.banner-style-two").count).to eq(0)
+      expect(Setting.where(key: "banner-style.banner-style-three").count).to eq(0)
+      expect(Setting.where(key: "banner-img.banner-img-one").count).to eq(0)
+      expect(Setting.where(key: "banner-img.banner-img-two").count).to eq(0)
+      expect(Setting.where(key: "banner-img.banner-img-three").count).to eq(0)
+      expect(Setting.where(key: "verification_offices_url").count).to eq(0)
+      expect(Setting.where(key: "not_deprecated").count).to eq(1)
+    end
+  end
 
   describe "#per_page_code_migration" do