Upgrade terraform and test clusters to 1.17 (#1901)

This updates test clusters to 1.17, as well as the kubectl client
version to match.

Initial smoke tests show that everything is working as expected at this
time.

build/build-image/Dockerfile

@@ -45,7 +45,7 @@ RUN go get -u golang.org/x/tools/cmd/goimports
 RUN gcloud components update && gcloud components install app-engine-go
 
 # the kubernetes version for the file
-ENV KUBERNETES_VER 1.16.15
+ENV KUBERNETES_VER 1.17.13
 
 # overwrite kubectl as we want a specific version
 RUN curl -LO https://storage.googleapis.com/kubernetes-release/release/v${KUBERNETES_VER}/bin/linux/amd64/kubectl && \

build/e2e-image/Dockerfile

@@ -15,7 +15,7 @@ RUN wget -q https://dl.google.com/go/go${GO_VERSION}.linux-amd64.tar.gz && \
 ENV PATH /usr/local/go/bin:/go/bin:$PATH
 
 # install kubectl without gcloud as we want the last version
-ENV KUBECTL_VER 1.16.15
+ENV KUBECTL_VER 1.17.13
 RUN curl -LO https://storage.googleapis.com/kubernetes-release/release/v${KUBECTL_VER}/bin/linux/amd64/kubectl && \
     chmod go+rx ./kubectl && \
     mv ./kubectl /usr/local/bin/kubectl

install/terraform/modules/gke/cluster.tf

@@ -29,7 +29,7 @@ locals {
   initialNodeCount  = lookup(var.cluster, "initialNodeCount", "4")
   network           = lookup(var.cluster, "network", "default")
   subnetwork        = lookup(var.cluster, "subnetwork", "")
-  kubernetesVersion = lookup(var.cluster, "kubernetesVersion", "1.16")
+  kubernetesVersion = lookup(var.cluster, "kubernetesVersion", "1.17")
 }
 
 # echo command used for debugging purpose