ALB LoadBalancerName is not changeable

[Marcel]

Currently there is no way to change the LoadBalancerName of an ALB.

There should be added a property or use just "Name" for it.

These are the two possible options, but this is not enough, because it based on the StackName + StackVersion.

https://github.com/zalando-stups/senza/blob/master/senza/components/elastic_load_balancer_v2.py#L82