ansible-deploy interface does not work with Ansible 2.4

[Pavlo Shchelokovskyy]

Ansible 2.4 was released on Sept 19, 2017, and ansible-deploy interface does not work with it,
even discounting a number of deprecation warnings produced for constructs used in playbooks.

so far the problems seems to be:

- changed interface of CallbackPlugins (new required public method to implement)
- 'ansible_devices' fact on tinyipa ramdisk now produces much more than a single
  '/dev/vda' device, which fails the gate job (a zero-sized '/dev/zram0' was chosen as image target
  to write to).

[OpenStack Infra (hudson-openstack)]

Reviewed: https://review.openstack.org/505320
Committed: https://git.openstack.org/cgit/openstack/ironic-staging-drivers/commit/?id=0719dafc2f2b607ce52fe998b296f10cd6db4f22
Submitter: Jenkins
Branch: master

commit 0719dafc2f2b607ce52fe998b296f10cd6db4f22
Author: Pavlo Shchelokovskyy <email address hidden>
Date: Tue Sep 19 16:15:44 2017 +0000

    [ansible] fixes for Anible 2.4 compat

    - fix callback plugin (add a new public methdod)
    - ansible_devices fact now contains many more devices
      (at least with tinyipa ramdisk and virtual HW),
      so by default we now attempt to use only devices that
      have non-empty 'host' attribute, and thus are
      real block devices on some controller
      (not memory-mapped files, loop devices etc)

      + during provisioning, the default target for image
        when root device hints are absent will be the first such device
      + during cleaning, only such devices will be attempted to
        be cleaned

    Change-Id: Id2bfd1ed552ed566b14f6ac5b222c011ff918bee
    Closes-Bug: #1718361