do not use mirrors for security repositories

Security updates should always be fetched directly from the security servers.
Update securing-your-server.md

Added another step to save and quit visudo for users who are not fimiliar with vi. 
Changed the command to restart SSH to "sudo service sshd restart" from "sudo service ssh restart"
Update securing-your-server.md

Fail2ban is not present in CentOS repositories. You need to add EPEL to install it (https://fedoraproject.org/wiki/EPEL)
Update securing-your-server.md

Using systemctl syntax for restarting sshd on CentOS.
Formatting changes.
Add upgrade documentation for Ubuntu 14.04 from Ubuntu 12.04
Revert "Make changes to CentOS SSL certificate guide and rename for CentOS 6&7"

This reverts commit 16e90eb9f9f34415c4cc7e0af6e58bccbfaa329d.
Added note on root SSH login.
Merge pull request #2 from thetechstewart/ubuntu1204to1404

Added note on root SSH login.
Merge pull request #103 from drussell393/ubuntu1204to1404

Add upgrade documentation for Ubuntu 14.04 from Ubuntu 12.04
Merge pull request #91 from 9rj/patch-2

Update securing-your-server.md
fixed link in contribute.md
readded change from PR #100 lost during PR #103
Drupal 8 Guide
Drupal 8 Guide
Latest Drupal 8 guide
fixed broken path to SSL for CentOS guide
Use correct format for links

Added correct prefix for the MTR reports link.
syntax fix
Merge pull request #107 from James-TR/patch-1

Getting-Started uses wrong URL for MTR guide
Drupal 8 copy edited version.