Add release notes for v1.3.1
Add release notes for v1.3.1

dlorenc/minikube,dalehamel/minikube,dlorenc/minikube,dlorenc/minikube,kubernetes/minikube,kubernetes/minikube,dalehamel/minikube,warmchang/minikube,kubernetes/minikube,warmchang/minikube,kubernetes/minikube,dlorenc/minikube,kubernetes/minikube,warmchang/minikube,warmchang/minikube,dalehamel/minikube,dlorenc/minikube,dlorenc/minikube,warmchang/minikube,kubernetes/minikube,kubernetes/minikube,warmchang/minikube,dlorenc/minikube,warmchang/minikube,dlorenc/minikube