Reconsider use of CloudFormation template parameters

[AlexanderYastrebov]

CloudFormation template to create load balancers was initially introduced within https://github.com/zalando-incubator/kube-ingress-aws-controller/issues/42

It seems the idea was to have a static parameterized template. Over the time template generation was translated into the go code #111

Changes cloudformation template from a yaml template to use the library https://github.com/mweagle/go-cloudformation to generate the template using Go. This is needed because we want to dynamically add certificates to the stack, which is not possible with pure cloudformation.

and became more and more conditional.

Since template is in the code now it seems there is no value in having template parameters so we should consider removing them in favor of using values directly to simplify code structure (remove indirection), remove boilrerplate and ease maintenance.

Care must be taken to not trigger massive loadbalancer recreation caused by template change.