Add support for multiple hostnames

[camertron]

Kuby only supports configuring a single hostname for an application, but as far as I know there's no actual Kubernetes-enforced limit on the number of hostnames allowed per ingress object. I propose using the existing hostname method to add hostnames to a list instead of the current behavior which simply replaces any previously configured hostname. In other words:

add_plugin :rails_app do
  hostname 'whatever.mydomain.com'
  hostname 'whatever2.mydomain.com'
end

See #112

[madlad33]

Hey, @camertron can I please pick this up?

[camertron]

@madlad33 absolutely, thank you!

[camertron]

Just a heads-up, someone with the handle @andersmarkc submitted and immediately closed two pull requests that appear to be addressing this issue. Not sure what's going on there. Perhaps consider coordinating with them?

[andersmarkc]

@camertron was trying to create a pull request to my own fork and f it up 2 times my bad, @madlad33 have a go at it if you fix it will save me a lot of time 👍

[madlad33]

Sure @andersmarkc, thanks!

[NikoDyring]

Sure @andersmarkc, thanks!

Sick @madlad33, thanks for picking up the issue. Please ping me whenever you have a PR 👍🏻