Implementation neutron metering resources

Current blueprint propose implementation neutron metering resources in heat.
Original description of neutron metering system: (https://wiki.openstack.org/wiki/Neutron/Metering/Bandwidth)

Implementation plan:

- create resource OS::Neutron::MeterLabel

attributes_schema = {
      'name': _('Name of the label.'),
       'description': _('Description of the label.'),
       'tenant_id': _('Tenant owning the label.'),
}

property_schema = {
         'name': {
             'Type': 'String',
             'Description': _('Name of the label.')},
         'description': {
             'Type': 'String',
             'Description': _('Description of the label.')},
          'tenant_id': {
             'Type': 'String',
             'Description': _('Tenant owning the label.')},
}

- create resource OS::Neutron::MeterRule

attributes_schema = {
     'direction' : _('Direction of traffic.'),
     'excluded' : _('Exclude state for cidr.'),
     'metering_label' : _('ID of metering label.'),
     'remote_ip_prefix' : _(' cidr to match.'),
}

property_schema = {
         'label': {
             'Type': 'String',
             'Description': _('Name of the label for metering.')},
         'remote_ip_prefix': {
             'Type': 'String',
             'Description': _('cidr to match on.')},
         'direction': {
             'Type': 'String',
             'AllowedValues' : ['ingress', 'egress'],
             'Default' : 'ingress',
             'Description': _('Direction of traffic, default:ingress.')},
          'excluded': {
             'Type': 'Boolean',
             'Default' : 'False',
             'Description': _('Exclude this cidr from the label, default:not excluded.')},
          'tenant_id': {
             'Type': 'String',
             'Description': _(Tenant owning the rule.')},
}