Make url configurable on the command call

[jmcs]

No description provided.

[prayerslayer]

What is the use case for this? It makes sense in pierone-cli as we have two of them, but there is only one Kio.

[jmcs]

I need to use kio from lizzy. I want to make the url configurable with an environmental variable, and I would prefer not having to write a config file on startup, with this option I can just pass the URL in every call.

[prayerslayer]

Hmm to me that sounds like a special use case where you already have a solution to (echo "{ url: <kio url> }" > ~/.config/kio.yaml) but very few other people would benefit from it. I'd rather not introduce that change, but I'm not the maintainer, so don't listen to me.

[hjacobs]

@jmcs I agree with @prayerslayer, but I propose an alternative: we can make the config loading generic to consider environment variables too

[hjacobs]

@jmcs zalando-stups/stups-cli-support#3

[hjacobs]

Changed the stups-cli-support to allow overwritting via ENV vars.