(maint) Remove require_relative for Ruby 1.8.7
(maint) Remove require_relative for Ruby 1.8.7

 - Because this module can be run on Puppet 3.8, which can run on
   the system Ruby of a Linux machine (such as CentOS 6), it's
   possible that the cdoe will be parsed in a Ruby 1.8.7 environment.

   Move to require with a manually constructed path, which is the
   effectively the same thing as require_relative in newer Rubies.

ferventcoder/puppetlabs-powershell,jpogran/puppetlabs-powershell,puppetlabs/puppetlabs-powershell,jpogran/puppetlabs-powershell,Iristyle/puppetlabs-powershell