Change k8s version from stable->master to stay up to date with cos changes in cluster/gce/config-default.sh

Author: amacaskill

test/run-k8s-integration.sh

@@ -17,8 +17,8 @@ readonly do_driver_build="${GCE_PD_DO_DRIVER_BUILD:-true}"
 readonly do_k8s_build="${GCE_PD_DO_K8S_BUILD:-false}"
 readonly deployment_strategy=${DEPLOYMENT_STRATEGY:-gce}
 readonly gke_cluster_version=${GKE_CLUSTER_VERSION:-latest}
-readonly kube_version=${GCE_PD_KUBE_VERSION:-stable}
-readonly test_version=${TEST_VERSION:-stable}
+readonly kube_version=${GCE_PD_KUBE_VERSION:-latest}
+readonly test_version=${TEST_VERSION:-latest}
 readonly gce_zone=${GCE_CLUSTER_ZONE:-us-central1-b}
 readonly gce_region=${GCE_CLUSTER_REGION:-}
 readonly image_type=${IMAGE_TYPE:-cos_containerd}