Make gocd-cli work when no security is configured for the server

[varshavaradarajan]

This is probably useful when people are using gocd trial and have no auth configured. Currently, doing ./gocd cr export up42 --plugin-id yaml.config.plugin when there's no auth to configure gives API auth is not configured. May be provide an option for gocd config auth-basic and gocd config auth-token to take none?

[tomzo]

An auth-none would be more appropriate, I think. We are not sending any auth headers to insecure server.

[marques-work]

@tomzo @varshavaradarajan I like the explicitness of auth-none and shouldn't be too hard to implement. I've been heads-down for the last couple of months in improving the Add Pipeline page, but I'll get back to CLI work soon. I have a ton of changes to unspool from my stash :)