Use dict.pop(key, None) instead of del dict[key]. dict.pop will not
raise any error when the key is not exist.

TrivialFix

Change-Id: I3808fc865afe6936a5d93eff792e1d1a93ba2085

In some part in the code we import objects. In the Openstack style
guidelines they recommend to import only modules.

http://docs.openstack.org/developer/hacking/#imports

Change-Id: I4b55cae8c2672f82025a95112b14d441d66f9d6d

- This change indroduces a merge_yaml action_plugin
- This change generates bifrost yaml configs.

Change-Id: I9814e6a5d55cbd46c4b60c06ed70ed54a575bd2f
Implements: blueprint bifrost-support

In links: http://pythonhosted.org/six/, we know 'cStringIO' is
a module of python 2.x, but in python3.x module 'io' has the
same function as 'cStringIO' in python2.x. So here we use
six.stringIO instead.

TrivialFix.

Change-Id: I8022b92b186e239cd76a36dab7766301bf96d2c4

Ansible 2.1.0 has lots of change and the plugin is not compatible
between 2.0.0 and 2.1.0. This change fix the gap.

* fix the signature change for _make_tmp_path in ansible 2.1.0
* fix the common_options in the kolla_docker.py

Change-Id: I05f5f05581c8bd625cd868fa0db549d0c60a7043
Closes-Bug: #1586018

DocImpact

Change-Id: I3cdfbf84919de80f535c030bd146787ecda40dec
partial-Implements: blueprint ansible2

By ignoring the appropriate tests that pep8 does we can properly run
*most* of the pep8 tests on all of our modules allowing for a more
consistent coding style.

Closes-Bug: #1528431
Change-Id: I33f27a250d06d4f044267aa3ad189e092789b8df

Convert config creation from a playbook to an action_plugin. This
reduces the complexity and confusion while retaining the same augment
structure and flexibility.

This allows us to remove the 0-byte files as requirements. They will
still be used if they are present (this means we require additional
documentation around them).

DocImpact
Closes-Bug: #1528430
Change-Id: I2c789f6be9f195c7771ca093a6d59499564b4740