Append openstacklib/lib to load path for type

As we discovered before[1] with puppet-keystone, rspec-puppet has
trouble loading paths in some circumstances. This patch updates the
$LOAD_PATH in the newly rewritten glance_image type so that unit tests
in other modules can properly load the openstacklib backend.

[1] https://bugs.launchpad.net/puppet-keystone/+bug/1408531

Change-Id: Ifa3cbd46b8b32695848d4c2e8f837881c46a7d98

lib/puppet/type/glance_image.rb

@@ -1,3 +1,4 @@
+File.expand_path('../../../../openstacklib/lib', File.dirname(__FILE__)).tap { |dir| $LOAD_PATH.unshift(dir) unless $LOAD_PATH.include?(dir) }
 Puppet::Type.newtype(:glance_image) do
   desc <<-EOT
     This allows manifests to declare an image to be