Resolve dynamic inventory libs through symlink
Resolve dynamic inventory libs through symlink

The new dynamic inventory lib path appending is broken when
dynamic_inventory is being called through a symlink[1].

This will resolve the correct, real path of the
dynamic_inventory.py script even if it is being executed
via a symlink, and then add the correct path to the libs.

[1]: https://github.com/Logan2211/openstack-ansible-overlay/tree/master/overlay/playbooks/inventory

Change-Id: I2594ab833e074c9727f051f061bd4590eaf0264f

weezer/openstack-ansible,weezer/openstack-ansible,BjoernT/os-ansible-deployment,BjoernT/openstack-ansible,stackforge/os-ansible-deployment,BjoernT/os-ansible-deployment,openstack/openstack-ansible,BjoernT/openstack-ansible,os-cloud/os-ansible-deployment,bunchc/openstack-ansible,cloudnull/os-ansible-deployment,yanyao/openstack-ansible,robb-romans/openstack-ansible,yanyao/openstack-ansible,Logan2211/openstack-ansible,os-cloud/os-ansible-deployment,openstack/openstack-ansible,cloudnull/os-ansible-deployment,stackforge/os-ansible-deployment,robb-romans/openstack-ansible,BjoernT/os-ansible-deployment,cfarquhar/openstack-ansible,bunchc/openstack-ansible,cfarquhar/openstack-ansible,Logan2211/openstack-ansible