.rubocop.yml in onebox-1.8.39 vs .rubocop.yml in onebox-1.8.40

@@ -1,6 +1,6 @@
 AllCops:
-  TargetRubyVersion: 2.2
+  TargetRubyVersion: 2.3
   DisabledByDefault: true
   Include:
     - '**/*.gemspec'
     - '**/Rakefile'
   Exclude: []