yum upgrade isn't really required to install docker-io (unless there's something I missed). There would be people who don't want to upgrade their system for whatever reason.

yum install docker-io should take care of installing the deps. The yum install should also pull the latest repo information at the time of install. If people experience trouble (mismatched/outdated versions), we'll update the rpms accordingly to handle them(bug reports welcome :) )

Which reminds me, I'll need to add a 'yum update docker-io' to update just the package.