One way to improve the performance of Ansible is through fact caching.
Rather than gather facts in every play, we can configure Ansible to
cache them in a persistent store. An example Ansible configuration for
doing this is as follows:

[defaults]
gathering = smart
fact_caching = jsonfile
fact_caching_connection = ./facts
fact_caching_timeout = 86400

While this mostly just works, there are a few places where we
unconditionally gather facts using the setup module. This change
modifies these to only gather facts when necessary.

We no longer execute the MichaelRigart.interfaces role using become:
true, since it may gather facts and we do not want it to do so as root.
The role uses become where necessary.

Change-Id: I9984a187fc6c0496ada489bb8eef36e44d695aac
Story: 2007492
Task: 39216

In a deployment that has both Ceph or Swift deployed it can be useful to seperate the network traffic.
This change adds support for dedicated storage networks for both Ceph and Swift. By default, the storage hosts are
attached to the following networks:

* Overcloud admin network
* Internal network
* Storage network
* Storage management network

This adds four additional networks, which can be used to seperate the storage network traffic as follows:

* Ceph storage network (ceph_storage_net_name) is used to carry Ceph storage
  data traffic. Defaults to the storage network (storage_net_name).
* Ceph storage management network (ceph_storage_mgmt_net_name) is used to carry
  storage management traffic. Defaults to the storage management network
  (storage_mgmt_net_name).
* Swift storage network (swift_storage_net_name) is used to carry Swift storage data
  traffic. Defaults to the storage network (storage_net_name).
* Swift storage replication network (swift_storage_replication_net_name) is used to
  carry storage management traffic. Defaults to the storage management network
  (storage_mgmt_net_name).

This change also includes several improvements to Swift device management and ring generation.

The device management and ring generation are now separate, with device management occurring during
'kayobe overcloud host configure', and ring generation during a new command, 'kayobe overcloud swift rings generate'.

For the device management, we now use standard Ansible modules rather than commands for device preparation.
File system labels can be configured for each device individually.

For ring generation, all commands are run on a single host, by default a host in the Swift storage group.
A python script runs in one of the kolla Swift containers, which consumes an autogenerated YAML config file that defines
the layout of the rings.

Change-Id: Iedc7535532d706f02d710de69b422abf2f6fe54c