Bump default etcd version to v3.3.10

Kubeadm v1.14 requires an etcd version greater than v3.2.18.
(https://github.com/kubernetes/kubernetes/blob/v1.14.0/cmd/kubeadm/app/constants/constants.go#L257)

Bump the default etcd version to v3.3.10, which is the default version
used in the Kubernetes v1.14 release.
(https://github.com/kubernetes/kubernetes/blob/master/CHANGELOG-1.14.md#external-dependencies)

Fixes vmware-archive#178

Signed-off-by: Alexander Brand <alexbrand09@gmail.com>

ansible/roles/etcd/defaults/main.yml

@@ -2,4 +2,4 @@
 etcd_enable: True
 etcd_cluster_token: 444fddcc-beae-45bc-9da6-d941d446b595
 etcd_interface: eth0
-etcd_version: v3.2.10
+etcd_version: v3.3.10