Update build_guide.md
Update build_guide.md

Added cross to make arguments to get binaries for all platforms
dlorenc/minikube,warmchang/minikube,dalehamel/minikube,warmchang/minikube,warmchang/minikube,dlorenc/minikube,dlorenc/minikube,kubernetes/minikube,dlorenc/minikube,warmchang/minikube,warmchang/minikube,warmchang/minikube,kubernetes/minikube,dlorenc/minikube,dalehamel/minikube,kubernetes/minikube,kubernetes/minikube,warmchang/minikube,dlorenc/minikube,kubernetes/minikube,dlorenc/minikube,kubernetes/minikube,dlorenc/minikube,dalehamel/minikube,kubernetes/minikube