(MODULES-1247) Update Puppet / PE compatibility

 - Given this module now requires FFI, it's important to verify in our
   MSI packages, which versions shipped with at least 1.9.x.  It appears
   that Puppet Open Source introduced a win32-dir upgrade to 0.4.3 for
   the release of 3.3.0.  Since win32-dir requires FFI, FFI will be
   present in MSIs released from this point in time:
   https://github.com/puppetlabs/puppet-win32-ruby/commits/1.9.3/ruby/lib/ruby/gems/1.9.1/gems/ffi-1.9.0-x86-mingw32/ext/ffi_c/ffi.c
 - Since PE 3.1 ships with Puppet open source 3.3.1, it should also be
   compatible.
 - Note that the Gemfile wasn't updated until Puppet open source 3.3.2,
   but given it's rare to run Puppet from source on Windows, it's
   safe to ignore that particular discrepancy:
 https://github.com/puppetlabs/puppet/commit/11f7c51bd860b86d183120735a7ea6c60e38993f