refactor create_server method for easier testing

lib/beaker/hypervisor/hcloud.rb

@@ -81,23 +81,32 @@ def vm_deletion_date
       date
     end
 
+    def create_hcloud_server(client, **kwargs)
+      action, server, _password, _next_action = client.servers.create(**kwargs)
+
+      while action.status == 'running'
+        sleep 5
+        action = client.actions.find(action.id)
+      end
+
+      server
+    end
+
     def create_server(host)
       @logger.notify "provisioning #{host.name}"
       location = host[:location] || 'nbg1'
       server_type = host[:server_type] || 'cx11'
-      action, server, _password, _next_action = @client.servers.create(
-        name: host.hostname,
-        location: location,
-        server_type: server_type,
-        image: host[:image],
-        ssh_keys: [ssh_key_name],
-        labels: { delete_vm_after: vm_deletion_date },
+      server = create_hcloud_server(
+        @client,
+        **{
+          name: host.hostname,
+          location: location,
+          server_type: server_type,
+          image: host[:image],
+          ssh_keys: [ssh_key_name],
+          labels: { delete_vm_after: vm_deletion_date },
+        },
       )
-      while action.status == 'running'
-        sleep 5
-        action = @client.actions.find(action.id)
-        server = @client.servers.find(server.id)
-      end
       host[:ip] = server.public_net['ipv4'].ip
       host[:vmhostname] = server.public_net['ipv4'].dns_ptr.find { |hash| hash['ip'] == host[:ip] }['dns_ptr']
       host[:hcloud_id] = server.id