documentation to reflect changes at https://github.com/theforeman/foreman/pull/1730 - Top level object hash are now marked as required.
Release 1.6.1
Merge remote-tracking branch 'shlomizadok/gh-pages' into gh-pages

Ticket #7261 is included in Foreman 1.6.1
Add CVE-2014-3691
Release 1.6.2, 1.5.4
added centos7 specific details and further checks to tftp documentation
Merge pull request #273 from Riptawr/gh-pages

added centos7 specific details and further checks to tftp documentation
Added SELinux instructions to libvirt ssh setup
Merge pull request #272 from lzap/ssh-selinux

Added SELinux instructions to libvirt ssh setup
added full path to config file ignored_environments.yml
fixed typos from previous commit
Merge pull request #279 from Riptawr/gh-pages

added full path to config file ignored_environments.yml, fixed typo