Rubocop fixes.
Rubocop fixes.

interactive-investor-ltd/postfix,mawatech/postfix,CarnegieLearningWeb/chef-postfix,Lostmyname/postfix,interactive-investor-ltd/postfix,zuazo-forks/chef-cookbooks-postfix,chrisjbray/postfix,opscode-cookbooks/postfix,voroniys/postfix,gnowxilef/cookbook-postfix,zuazo-forks/chef-cookbooks-postfix,gnowxilef/cookbook-postfix,mlyndaker/postfix,CarnegieLearningWeb/chef-postfix,chef-cookbooks/postfix,opscode-cookbooks/postfix,mawatech/postfix,yakara-ltd/postfix,chrisjbray/postfix,Lostmyname/postfix,chef-cookbooks/postfix,mlyndaker/postfix,voroniys/postfix,leoditommaso/postfix,yakara-ltd/postfix,nilroy/postfix,leoditommaso/postfix,nilroy/postfix