Update contributing
Update contributing

pwnieexpress/apt,BarthV/apt,Alukardd/cookbook-apt,PolicyStat/apt,protec-cookbooks/apt,edmunds-chef/apt,Altiscale/apt,h4ck3rm1k3/apt,edmunds-chef/apt,h4ck3rm1k3/apt,Tealium/apt,Rockstar04/apt,opscode-cookbooks/apt,patcon/apt,pwnieexpress/apt,brumschlag/apt,chef-cookbooks/apt,balmbees/apt,opscode-cookbooks/apt,Rockstar04/apt,puckel/apt,scalarae/apt,protec-cookbooks/apt,patcon/apt,Alukardd/cookbook-apt,scalarae/apt,chef-cookbooks/apt,puckel/apt,Tealium/apt,PolicyStat/apt,BarthV/apt,balmbees/apt,brumschlag/apt,Altiscale/apt