Use inventory instead of hostfile parameter
Use inventory instead of hostfile parameter

The hostfile parameter in ansible.cfg is deprecated per documentation:
http://docs.ansible.com/ansible/intro_configuration.html#hostfile

This small patch update the hostfile parameter to inventory

Change-Id: I16a63c728d59799d70d2d1414aacf9a17eafcfb5
(cherry picked from commit 50851d55f90b66627b95517a94dbf9872f2859a9)

VaneCloud/openstack-ansible,yanyao/openstack-deployment,yanyao/openstack-deployment,VaneCloud/openstack-ansible,yanyao/openstack-deployment,yanyao/openstack-deployment,VaneCloud/openstack-ansible