Sticker for CentOS Promo

 Changes to be committed:

	new file:   stickers/CentOS-Powered.svg

	new file:   stickers/Powered-CentOS.svg

	new file:   stickers/Powered-by-CentOS.svg

	new file:   stickers/stickers-pakc-centos.svg

All sticker are CC-By
Merge pull request #4 from williamjmorenor/master

Sticker for CentOS Promo