Add test for sending questions to banned users

spec/workers/question_worker_spec.rb

@@ -40,5 +40,16 @@ describe QuestionWorker do
             .to(4)
         )
     end
+
+    it "does not send questions to banned users" do
+      user.followers.first.ban
+
+      expect { subject }
+        .to(
+          change { Inbox.where(user_id: user.followers.ids, question_id: question_id, new: true).count }
+            .from(0)
+            .to(4)
+        )
+    end
   end
 end