Add help for aptible config:add

[justinwiley]

$ aptible config:add
Could not find app in current working directory, please specify with --app
$ aptible config:add --app my-app
Updating configuration and restarting app...

So without arguments, config:add restarts the app. It would be better to have some explanatory text like "You didn't specify what you wanted to add. Do XYZ"

[fancyremarker]

Hey @justinwiley , this is certainly a bug. If no KEY=value arguments are passed, the command should exit in error with a useful message.