[kubeadm] use v1beta3 configuration version

* extra admission controls now don't have a version in their file names
  eventratelimit.v1beta2.yaml.j2 -> eventratelimit.yaml.j2
* cri_socket variable includes the unix:// prefix to be conformat with
  upstream

roles/kubernetes/kubeadm/templates/kubeadm-client.conf.v1beta3.j2

@@ -0,0 +1,28 @@
+---
+apiVersion: kubeadm.k8s.io/v1beta3
+kind: JoinConfiguration
+discovery:
+  bootstrapToken:
+{% if kubeadm_config_api_fqdn is defined %}
+    apiServerEndpoint: {{ kubeadm_config_api_fqdn }}:{{ loadbalancer_apiserver.port | default(kube_apiserver_port) }}
+{% else %}
+    apiServerEndpoint: {{ kubeadm_discovery_address }}
+{% endif %}
+    token: {{ kubeadm_token }}
+{% if kubeadm_ca_hash.stdout is defined %}
+    caCertHashes:
+    - sha256:{{ kubeadm_ca_hash.stdout }}
+{% else %}
+    unsafeSkipCAVerification: true
+{% endif %}
+  timeout: {{ discovery_timeout }}
+  tlsBootstrapToken: {{ kubeadm_token }}
+caCertPath: {{ kube_cert_dir }}/ca.crt
+nodeRegistration:
+  name: {{ kube_override_hostname }}
+  criSocket: {{ cri_socket }}
+{% if 'calico_rr' in group_names and 'kube_node' not in group_names %}
+  taints:
+  - effect: NoSchedule
+    key: node-role.kubernetes.io/calico-rr
+{% endif %}