Update docs from Kubernetes v1.17.4 to v1.18.0

aws/container-linux/kubernetes/README.md

@@ -11,7 +11,7 @@ Typhoon distributes upstream Kubernetes, architectural conventions, and cluster
 
 ## Features <a href="https://www.cncf.io/certification/software-conformance/"><img align="right" src="https://storage.googleapis.com/poseidon/certified-kubernetes.png"></a>
 
-* Kubernetes v1.17.4 (upstream)
+* Kubernetes v1.18.0 (upstream)
 * Single or multi-master, [Calico](https://www.projectcalico.org/) or [flannel](https://github.com/coreos/flannel) networking
 * On-cluster etcd with TLS, [RBAC](https://kubernetes.io/docs/admin/authorization/rbac/)-enabled, [network policy](https://kubernetes.io/docs/concepts/services-networking/network-policies/)
 * Advanced features like [worker pools](https://typhoon.psdn.io/advanced/worker-pools/), [spot](https://typhoon.psdn.io/cl/aws/#spot) workers, and [snippets](https://typhoon.psdn.io/advanced/customization/#container-linux) customization

aws/container-linux/kubernetes/workers/cl/worker.yaml

@@ -127,7 +127,7 @@ storage:
             --volume config,kind=host,source=/etc/kubernetes \
             --mount volume=config,target=/etc/kubernetes \
             --insecure-options=image \
-            docker://quay.io/poseidon/kubelet:v1.17.4 \
+            docker://quay.io/poseidon/kubelet:v1.18.0 \
             --net=host \
             --dns=host \
             -- \