Check if Roxy environment exist

[rlouapre]

From a shell script how can I check if an environment exists?

ml bootstrap wrong-environment will still have a return code 0.

[joemfb]

I was going to suggest ./ml <env> info, but that has a return code of 0 whether the environment exists or not. Sounds like both of those commands need updates.

[grtjn]

I assume we mean MarkLogic connectivity here, right? I think #367 would be useful for that.