Updates rubocop gems

- Manually specifies minor version so it doesn't automatically update minor verison during CI tests.
- Updates other rubocop gems.
- Resolves cops

.rubocop_todo.yml

@@ -10,7 +10,7 @@ Metrics/AbcSize:
   Max: 20 # Goal: 15
 
 Metrics/CyclomaticComplexity:
-  Max: 7 # Goal: 6
+  Max: 8 # Goal: 7
 
 Metrics/PerceivedComplexity:
   Max: 9 # Goal: 7

lib/paper_trail/events/base.rb

@@ -247,8 +247,7 @@ module PaperTrail
       # @api private
       def prepare_object_changes(changes)
         changes = serialize_object_changes(changes)
-        changes = recordable_object_changes(changes)
-        changes
+        recordable_object_changes(changes)
       end
 
       # Returns an object which can be assigned to the `object_changes`

paper_trail.gemspec

@@ -44,9 +44,9 @@ has been destroyed.
   s.add_development_dependency "paper_trail-association_tracking", "~> 2.0.0"
   s.add_development_dependency "rake", "~> 13.0"
   s.add_development_dependency "rspec-rails", "~> 4.0"
-  s.add_development_dependency "rubocop", "~> 0.85.1"
-  s.add_development_dependency "rubocop-performance", "~> 1.4"
-  s.add_development_dependency "rubocop-rspec", "~> 1.35"
+  s.add_development_dependency "rubocop", "~> 0.88.0"
+  s.add_development_dependency "rubocop-performance", "~> 1.7.1"
+  s.add_development_dependency "rubocop-rspec", "~> 1.42.0"
 
   # ## Database Adapters
   #

spec/dummy_app/config.ru

@@ -2,5 +2,5 @@
 
 # This file is used by Rack-based servers to start the application.
 
-require ::File.expand_path("../config/environment", __FILE__)
+require ::File.expand_path("config/environment", __dir__)
 run Dummy::Application

spec/models/version_spec.rb

@@ -12,7 +12,7 @@ module PaperTrail
         specify { expect(PaperTrail.serializer).to be PaperTrail::Serializers::YAML }
 
         it "store out as a plain hash" do
-          expect(value =~ /HashWithIndifferentAccess/).to be_nil
+          expect(value).not_to include("HashWithIndifferentAccess")
         end
       end
 
@@ -46,7 +46,7 @@ module PaperTrail
         end
 
         it "store out as a plain hash" do
-          expect(value =~ /HashWithIndifferentAccess/).to be_nil
+          expect(value).not_to include("HashWithIndifferentAccess")
         end
 
         after do