Update refs to kubernetes version to v1.8.0 (#1845)

README.md

@@ -54,7 +54,7 @@ Versions of supported components
 --------------------------------
 
 
-[kubernetes](https://github.com/kubernetes/kubernetes/releases) v1.7.3 <br>
+[kubernetes](https://github.com/kubernetes/kubernetes/releases) v1.8.0 <br>
 [etcd](https://github.com/coreos/etcd/releases) v3.2.4 <br>
 [flanneld](https://github.com/coreos/flannel/releases) v0.8.0 <br>
 [calico](https://docs.projectcalico.org/v2.5/releases/) v2.5.0 <br>

roles/kubespray-defaults/defaults/main.yaml

@@ -8,7 +8,7 @@ kube_api_anonymous_auth: false
 is_atomic: false
 
 ## Change this to use another Kubernetes version, e.g. a current beta release
-kube_version: v1.6.7
+kube_version: v1.8.0
 
 # Set to true to allow pre-checks to fail and continue deployment
 ignore_assert_errors: false