Add documentation for creating a K8S cluster with GKE or Minikube (#166)

* Add documentation for creating a K8S cluster

The GKE instructions have been verified to work, but Minikube is a WIP.

* fix some formatting

* indent code block correctly

* Specify that this is Elafros-specific

creating-a-kubernetes-cluster.md

@@ -0,0 +1,104 @@
+# Creating a Kubernetes Cluster for Elafros
+
+Two options:
+
+* Setup a [GKE cluster](#gke)
+* Run [minikube](#minikube) locally
+
+## GKE
+
+To use a k8s cluster running in GKE:
+
+1.  Install `gcloud` using
+   [the instructions for your platform](https://cloud.google.com/sdk/downloads).
+
+2.  Create a GCP project (or use an existing project if you've already created
+    one) at http://console.cloud.google.com/home/dashboard. Set the ID of the
+    project in an environment variable (e.g. `PROJECT_ID`) along with the email
+    of your GCP user (`GCP_USER`).
+
+3.  Enable the k8s API:
+
+    ```shell
+    gcloud --project=$PROJECT_ID services enable container.googleapis.com
+    ```
+
+4.  Create a k8s cluster:
+
+    ```shell
+    gcloud --project=$PROJECT_ID container clusters create \
+      # Version 1.9+ is required
+      --cluster-version=1.9.2-gke.1 \
+      # Change this to whichever zone you choose
+      --zone=us-east1-d \
+      # cloud-platform scope is required to access GCB
+      --scopes=cloud-platform \
+      # Autoscale from 1 to 3 nodes. Adjust this for your use case
+      --enable-autoscaling --min-nodes=1 --max-nodes=3 \
+      # Change this to your preferred cluster name
+      elafros-demo
+    ```
+
+    You can see the list of supported cluster versions in a particular zone
+    by running:
+
+    ```shell
+    # Get the list of valid versions in us-east1-d
+    gcloud container get-server-config --zone us-east1-d
+    ```
+
+5. If you haven't installed `kubectl` yet, you can install it now with `gcloud`:
+
+    ```shell
+    gcloud components install kubectl
+    ```
+
+6.  Give your gcloud user cluster-admin privileges:
+
+    ```shell
+    kubectl create clusterrolebinding gcloud-admin-binding \
+        --clusterrole=cluster-admin \
+        --user=$GCP_USER
+    ```
+
+7. Enable the GCR API:
+
+   ```shell
+   gcloud --project=$PROJECT_ID service-management enable containerregistry.googleapis.com
+   ```
+
+8. Install the `docker-credential-gcr` helper so Docker (and Bazel) can
+   authenticate with GCR:
+
+   ```shell
+   gcloud components install docker-credential-gcr
+   ```
+
+9. Add the GCR credentials to the Docker config file:
+
+   ```shell
+   docker-credential-gcr configure-docker
+   ```
+
+Now you can use `gcr.io/$PROJECT_ID` as your Docker repo and your GKE
+cluster will automatically pull from it.
+
+## Minikube
+
+To run a k8s cluster locally, you will need to [install and configure
+minikube](https://github.com/kubernetes/minikube#minikube) with a [VM
+driver](https://github.com/kubernetes/minikube#requirements), e.g. `kvm` on
+Linux or `xhyve` on macOS.
+
+If this worked, you should be able to walk through [the minikube
+quickstart](https://github.com/kubernetes/minikube#quickstart) successfully.
+
+```shell
+minikube start \
+# Kubernetes version must be at least 1.9.0
+--kubernetes-version=v1.9.0 \
+# Use the VM driver you installed above
+--vm-driver=kvm
+```
+
+_TODO Add instructions for setting up a local registry_