Allow ability to choose the host port

[ahmetb]

It seems like kubehost bind always binds to port 80. As far as I can tell, this prevents kubehost to be used with multiple exposed services at once (#2) as it tries to reuse port 80.

[WilliamDenniss]

The deployment kubehost bind creates will use the same port specified by your clusterIP service.

Note that there is a current documented limitation that we only support services with one port (specifically: it'll use the first one it finds).

Here's the specific code: https://github.com/GoogleContainerTools/kubehost/blob/71d2a859cfba7172351200f2f0debb4d900c47e8/kubehost#L144