Add support for Kubernetes v1.16+

[robgmills]

extensions/v1beta1 were marked deprecated in Kubernetes
v1.16.

This enables support for newer versions of Kubernetes.

[robgmills]

Addresses #26

[weeco]

Hey @robgmills , looking at the PR I'd consider removing the ingress resource completely. But I wonder whether I'm missing something why you may want to use it?

[robgmills]

I actually don't use the ingress resource. I'm not sure if others are using it or what they might be using it for. I might guess that someone who has a sufficiently complex Kubernetes environment might want to expose the kube-eagle /metrics endpoint from their cluster for some reason. Maybe they're collecting these metrics off-cluster for some reason?

I thought this change was the least disruptive for all users, whether or not they use the ingress resource, to continue using this chart on newer versions of Kubernetes.

If you'd prefer, I'd be happy to remove the ingress resource instead! After all, "the best diff is a red diff!"

[weeco]

Thanks for your feedback, I think we can remove the ingress and see if this bothers someone. Would be nice if you could remove it, thank you!

[robgmills]

Superseded by #30. Closing.