Add configuration for swift auth in controller

The openstack::keystone class already supports the
ability to configure authorization for swift, but
it was not possible to set this configuration
in the openstack::controller class.

This commits adds two parameters to openstack::controller:
  - swift - Indicates that swift auth should be configured in keystone
  - swift_user_password - password to use for swift user in keystone

These commits allow swift to be configured together with this
controller class.

Change-Id: I93455da30786d41ae6e56b32f53f30fa57852df0