Added an example script for retreiving a GKE certificate
Added an example script for retreiving a GKE certificate

yacloud-io/teleport,gravitational/teleport,yacloud-io/teleport,yacloud-io/teleport,yacloud-io/teleport,yacloud-io/teleport,gravitational/teleport,gravitational/teleport,yacloud-io/teleport,gravitational/teleport,gravitational/teleport,gravitational/teleport,yacloud-io/teleport