'Returns a list of availability zones.
:return: ``list`` of :class:`ProfitBricksAvailabilityZone`
:rtype: ``list``'

def ex_list_availability_zones(self):

    availability_zones = []
    for (key, values) in self.AVAILABILITY_ZONE.items():
        name = copy.deepcopy(values)['name']
        availability_zone = ProfitBricksAvailabilityZone(name=name)
        availability_zones.append(availability_zone)
    return availability_zones
