Fix Rubocop unconfigured warnings

Author: ekohl

.rubocop.yml

@@ -56,10 +56,19 @@ Style/FrozenStringLiteralComment:
 Style/GuardClause:
   Enabled: false
 
+Style/HashEachMethods:
+  Enabled: true
+
 # Support both, Ruby 1.9 hashmap and hash-rocket syntax
 Style/HashSyntax:
   Enabled: false
 
+Style/HashTransformKeys:
+  Enabled: true
+
+Style/HashTransformValues:
+  Enabled: true
+
 Style/IfUnlessModifier:
   Enabled: false