[Docs] GKE version 1.14.10-gke.27 needs to be updated in Tutorials

Running this command
gcloud container clusters create my-cluster-us-east1 \
--cluster-version 1.14.10-gke.27 \
--region us-east1 \
--network my-network \
--subnetwork my-subnet-us-east1

threw an error

ERROR: (gcloud.container.clusters.create) ResponseError: code=400, message=Master version "1.14.10-gke.27" is unsupported.

This worked
gcloud container clusters create my-cluster-us-east1 \
--cluster-version 1.17.17-gke.3700 \
--region us-east1 \
--network my-network \
--subnetwork my-subnet-us-east1

Checked out this document for getting the stable version https://cloud.google.com/kubernetes-engine/versioning

gcloud container get-server-config --flatten="channels" --filter="channels.channel=STABLE" \
--format="yaml(channels.channel,channels.defaultVersion)" --region us-east1

—
channels:
channel: STABLE
defaultVersion: 1.17.17-gke.3700

E-mail: rekha.nair@couchbase.com