Activate EPEL repo if we are on RHEL6
Use the vagrant user instead of root
Use correct pip command for Linkchecker install
Install xz as it's needed for linkchecker unpacking
Set timezone with a copy instead of a symlink op
Use puppetlabs centos 6.4 box
Don't allow password logins
CentOS has py2.6, so the linkchecker path changes
Add http and mosh iptables rules, and setup EPEL for RHEL6