Fix a few coding standards issues:

* Remove extra empty lines before private keyword usages.

  specs:

  * Fix one long line;
  * use proc keyword instead of Proc.new.

lib/producer/core/cli.rb

@@ -32,7 +32,6 @@ module Producer
         end
       end
 
-
       private
 
       def print_usage_and_exit(status)