style(rubocop): Style/MissingRespondToMissing

lib/postal/message_db/delivery.rb

@@ -25,6 +25,10 @@ module Postal
         @attributes[name.to_s]
       end
 
+      def respond_to_missing?(name)
+        @attributes.has_key?(name.to_s)
+      end
+
       def timestamp
         @timestamp ||= @attributes["timestamp"] ? Time.zone.at(@attributes["timestamp"]) : nil
       end

lib/postal/message_db/message.rb

@@ -185,6 +185,11 @@ module Postal
         end
       end
 
+      def respond_to_missing?(name)
+        name = name.to_s.sub(/=\z/, "")
+        @attributes.has_key?(name.to_s)
+      end
+
       #
       # Has this message been persisted to the database yet?
       #