mixlib-shellout update to 1.6.1

* Update lockfile for repo to pin 1.6.1
* pull in 1.0.68 of oc-chef-pedant which contains the same change

update oc-chef-pedant to version w/ correct mixlib
Merge pull request #628 from opscode/mixlib-shellout-1.6.1-12.0

mixlib-shellout update to 1.6.1
Update to Omnibus 4
Move highline-gem to omnibus-software
Remove mysql2 (as comment indicates - it is no longer needed)
Move pg-gem to omnibus-software
Move redis-rb to redis-gem in omnibus-software
Move sequel-gem to omnibus-software
Add the omnibus.rb configuration file to the repo
Remove rpm-signing (this is in Omnibus core now)
Remove package_links (@sdelano said they were no longer used)
Update project definition to use the new hotness

Conflicts:
	config/projects/chef-server.rb
Update bookshelf to use the new Omnibusisms
Update enterprise-chef-server-schema to use the new Omnibusisms
Update knife-ec-backup-gem to use the new Omnibusisms
Update to omnibus cookbook 2.3.4
Lock Test Kitchen to specific Chef version

Using a version of “latest” is playing with fire, go ask @lamont-granquist
if you need to hear more.
Move to `perl_pg_driver` from omnibus-software
Update chef-ha-plugin-config to use the new Omnibusisms
Update knife-opc-gem to use the new Omnibusisms