Disable RHEL 6 due to timeouts
Disable RHEL 6 due to timeouts

Signed-off-by: Tim Smith <764ef62106582a09ed09dfa0b6bff7c05fd7d1e4@chef.io>

chef-cookbooks/chef-server,juliandunn/chef-server,GannettDigital/chef-server,vinyar/chef-server-1,jjasghar/chef-server