Fix: cluster/kube-up.sh curl timeout a little bit short.

In my environment, curl timeout a little bit short.
And kube-up.sh loop eternity because of curl timeout.

testing only curl is as follows.

```
$ curl --insecure --user user:password --max-time 1 https://xxx.xxx.xxx.xxx/api/v1beta1/pods
curl: (28) Operation timed out after 1292 milliseconds with 0 out of -1 bytes received
$  curl --insecure --user user:password --max-time 1 https://xxx.xxx.xxx.xxx/api/v1beta1/pods
curl: (28) Connection timed out after 1000 milliseconds
$  curl --insecure --user user:password --max-time 1 https://xxx.xxx.xxx.xxx/api/v1beta1/pods
curl: (28) Operation timed out after 1341 milliseconds with 0 out of -1 bytes received
```

Same settings and environments, the difference is timeout value is as follows.

```
$ curl --insecure --user user:password --max-time 5 https://xxx.xxx.xxx.xxx/api/v1beta1/pods
{
	"kind": "PodList",
	"items": []
}
$ curl --insecure --user user:password --max-time 5 https://xxx.xxx.xxx.xxx/api/v1beta1/pods
{
	"kind": "PodList",
	"items": []
}
$ curl --insecure --user user:password --max-time 5 https://xxx.xxx.xxx.xxx/api/v1beta1/pods
{
	"kind": "PodList",
	"items": []
}
```