Adds integrity check for badge descriptions

spec/integrity/i18n_spec.rb

@@ -16,6 +16,13 @@ describe "i18n integrity checks" do
     end
   end
 
+  it "has an i18n key for each badge description" do
+    Badge.where(system: true).each do |b|
+      expect(b.long_description).to be_present
+      expect(b.description).to be_present
+    end
+  end
+
   it "needs an i18n key (notification_types) for each Notification type" do
     Notification.types.each_key do |type|
       next if type == :custom || type == :group_message_summary