.rubocop.yml in d_heap-0.5.0 vs .rubocop.yml in d_heap-0.6.0

@@ -1,10 +1,10 @@
 inherit_mode:
   merge:
     - Exclude
 
 AllCops:
-  TargetRubyVersion: 2.5
+  TargetRubyVersion: 2.4
   NewCops: disable
   Exclude:
     - bin/benchmark-driver
     - bin/rake
     - bin/rspec