nova-placement-api support

[Alex Schultz]

We need to provide a way to configure the nova-placement-api. In RDO the package name is
openstack-nova-placement-api and the configuration that is included in this package is:

# cat /etc/httpd/conf.d/00-nova-placement-api.conf
Listen 8778

<VirtualHost *:8778>
  WSGIProcessGroup nova-placement-api
  WSGIApplicationGroup %{GLOBAL}
  WSGIPassAuthorization On
  WSGIDaemonProcess nova-placement-api processes=3 threads=1 user=nova group=nova
  WSGIScriptAlias / /usr/bin/nova-placement-api
  <IfVersion >= 2.4>
    ErrorLogFormat "%M"
  </IfVersion>
  ErrorLog /var/log/nova/nova-placement-api.log
  #SSLEngine On
  #SSLCertificateFile ...
  #SSLCertificateKeyFile ...
</VirtualHost>

Alias /nova-placement-api /usr/bin/nova-placement-api
<Location /nova-placement-api>
  SetHandler wsgi-script
  Options +ExecCGI
  WSGIProcessGroup nova-placement-api
  WSGIApplicationGroup %{GLOBAL}
  WSGIPassAuthorization On
</Location>

We need to add support for configuring this within the puppet manifests as we remove the /etc/httpd/conf.d/00-nova-placement-api.conf file when we deploy apache.