Update master node label

Reflecting: [PR107](geerlingguy/ansible-role-kubernetes#107)

Author: weshouman

kubernetes/inventory

@@ -1,5 +1,5 @@
 [k8s-master]
-master ansible_host=192.168.56.2 kubernetes_role=master
+master ansible_host=192.168.56.2 kubernetes_role=control_plane
 
 [k8s-nodes]
 node1 ansible_host=192.168.56.3 kubernetes_role=node
@@ -11,4 +11,4 @@ k8s-nodes
 
 [k8s:vars]
 ansible_user=vagrant
-ansible_ssh_private_key_file=~/.vagrant.d/insecure_private_key
+ansible_ssh_private_key_file=~/.vagrant.d/insecure_private_key