.rubocop.yml in socrates-0.1.21 vs .rubocop.yml in socrates-0.1.22

- old
+ new

@@ -1,5 +1,8 @@
 inherit_from:
   - https://raw.githubusercontent.com/carbonfive/c5-conventions/master/rubocop/rubocop.yml
 
+AllCops:
+  TargetRubyVersion: 2.4
+
 Naming/UncommunicativeMethodParamName:
   Enabled: false