core: update cluster-proportional-autoscaler to v1.1.2
core: update cluster-proportional-autoscaler to v1.1.2

This updates the image version for cluster-proportional-autoscaler to v1.1.2
This version uses client-go 3.0 beta which is fully compatible with k8s 1.6

kubernetes-incubator/kube-aws,danielfm/kube-aws,iflix-letsplay/kube-aws,mumoshu/kube-aws,camilb/kube-aws,HotelsDotCom/kube-aws,c-knowles/kube-aws,danielfm/kube-aws,mumoshu/kube-aws,iflix-letsplay/kube-aws,camilb/kube-aws,c-knowles/kube-aws,HotelsDotCom/kube-aws,kubernetes-incubator/kube-aws