Fix wrong link to helm inst guide. Add note to avoid error with helm and minikube.

Change-Id: I8749d4eb2b8e7f9404128c2f41713e67e93d7867
diff --git a/prereqs/helm.md b/prereqs/helm.md
index e00e831..140084e 100644
--- a/prereqs/helm.md
+++ b/prereqs/helm.md
@@ -19,9 +19,11 @@
 
 Helm can be installed on any device able to reach the Kubernetes POD (i.e. the developer laptop, another server in the network). Tiller should be installed on the Kubernetes pod itself, through the kubectl CLI.
 
+> **Note**: if you've installed Minikube you'll likely need to install *socat* as well before proceeding, otherwise errors will be thrown. For example, on Ubuntu do *sudo apt-get install socat*.
+
 ### Install helm client
 
-Follow the instructions at <https://docs.helm.sh/using_helm/#installing-helm>
+Follow the instructions at <https://github.com/kubernetes/helm/blob/master/docs/install.md#installing-the-helm-client>
 
 ### Install tiller