Convert specs to RSpec 2.99.2 syntax with Transpec

This conversion is done by Transpec 3.1.0 with the following command:
    transpec

* 424 conversions
    from: obj.should
      to: expect(obj).to

* 325 conversions
    from: == expected
      to: eq(expected)

* 38 conversions
    from: obj.should_not
      to: expect(obj).not_to

* 15 conversions
    from: =~ /pattern/
      to: match(/pattern/)

* 9 conversions
    from: it { should ... }
      to: it { is_expected.to ... }

* 5 conversions
    from: lambda { }.should_not
      to: expect { }.not_to

* 4 conversions
    from: lambda { }.should
      to: expect { }.to

* 2 conversions
    from: -> { }.should
      to: expect { }.to

* 2 conversions
    from: -> { }.should_not
      to: expect { }.not_to

* 1 conversion
    from: === expected
      to: be === expected

* 1 conversion
    from: =~ [1, 2]
      to: match_array([1, 2])

For more details: https://github.com/yujinakayama/transpec#supported-conversions

spec/models/category_user_spec.rb

@@ -57,7 +57,7 @@ describe CategoryUser do
       CategoryUser.create!(user: user, category: watched_category, notification_level: CategoryUser.notification_levels[:watching])
 
       post = create_post
-      TopicUser.get(post.topic, user).should be_blank
+      expect(TopicUser.get(post.topic, user)).to be_blank
 
       # Now, change the topic's category
       post.topic.change_category_to_id(watched_category.id)