prototypes: bifrost: Add keystone roles

prototypes: bifrost: Add keystone roles

The os_client_config Ansible module used by all the ironic-* roles
depends on the keystone roles so we need to make use of them even
though they do not affect the end result. This fixes the following
OPNFV CI problem due to not having a clouds.yaml file present to
be consumed by the os_client_config Ansible module.

fatal: [controller00]: FAILED! => {"censored": "the output has been hidden due to the fact that 'no_log: true' was specified for this result"}
An exception occurred during task execution. The full traceback is:
Traceback (most recent call last):
  File "/tmp/ansible_ApkCUQ/ansible_module_os_client_config.py", line 75, in <module>
    main()
  File "/tmp/ansible_ApkCUQ/ansible_module_os_client_config.py", line 63, in main
    for cloud in config.get_all_clouds():
  File "/usr/lib/python2.7/site-packages/os_client_config/config.py", line 798, in get_all_clouds
    cloud, region_name=region['name']))
  File "/usr/lib/python2.7/site-packages/os_client_config/config.py", line 1071, in get_one_cloud
    auth_plugin = loader.load_from_options(**config['auth'])
  File "/usr/lib/python2.7/site-packages/keystoneauth1/loading/base.py", line 162, in load_from_options
    raise exceptions.MissingRequiredOptions(missing_required)
keystoneauth1.exceptions.auth_plugins.MissingRequiredOptions: Auth plugin requires parameters which were not given: auth_url
fatal: [opnfv]: FAILED! => {"censored": "the output has been hidden due to the fact that 'no_log: true' was specified for this result"}

Moreover, we cleanup the ~/openstack directory which may contain some
bifrost artifacts such as a clouds.yaml file.

Finally, we use 'sudo -H' because for the keystone roles we need the HOME
variable to be set properly.

Change-Id: I45b08bd33dd8ea9505fe10eb4b2b10956b3b683c