Added 4 nodes req for bookinfo (#165)

* First draft getting started

* Added istio-installation and changed bookinfo

* Fix display issue

* Addressed code review comments

* Address more review comments, istio-ca not part of the install

* Use local files instead of raw github files

* Addressed more review comments

* Added note about istioctl and renamed istio-ingress-controller to istio-ingress

* Fix the verb tense

* Rename istio-ingress-controller to istio-ingress

* Fixed installation instructions

* Remove fault injection

* Fix uninstall

* Fix link

* Correct path

* Rbac clarification for alpha and beta versions

* Add more clarity

* Add a dot

* Fix display error

* Fix display error

* Add clarification for Ingress

* Update installation to point to latest release

* Added instructions

* Add more clarity in installation

* Add more clarity in installation

* Get rbac the right way

* Add 4 nodes

_docs/samples/bookinfo.md

@@ -13,8 +13,9 @@ This sample deploys a simple application composed of four separate microservices
 to demonstrate various features of the Istio service mesh.
 
 ## Before you begin
+* If you use GKE, please ensure your cluster has at least 4 standard GKE nodes.
 
-Setup Istio by following the instructions in the
+* Setup Istio by following the instructions in the
 [Installation guide]({{home}}/docs/tasks/installing-istio.html).
 
 ## Overview