.rubocop.yml in nutrella-1.2.1 vs .rubocop.yml in nutrella-1.2.2

@@ -1,6 +1,10 @@
+require:
+  - rubocop-performance
+  - rubocop-rspec
+
 AllCops:
-  TargetRubyVersion: 2.3
+  TargetRubyVersion: 2.4
 
   Exclude:
     - 'bin/**/*'
 
 # Rubocop and I cannot agree.