Exit 1 in case of CLI error

[matteofigus]

Fixes #174

Now that all the cli's facades have an optional callback (not used by the cli) - it is possible, in case it is not provided, to wrap it with a utility that exits with a process.exit(1) when a callback is fired with an error.

To test locally with unix/mac:

• checkout the branch locally
• run a command that should fail like node oc-cli.js registry add 23456
• run echo $? to see previous command's exit code

[matteofigus]

Can you review this @antwhite or @jankowiakmaria or @pbazydlo ?

[pbazydlo]

lgtm, it's a scary one though as you're now forcing death instead of silence, won't it break anything?

[pbazydlo]

(outside of oc itself)

[matteofigus]

@pbazydlo that's what we want if the callback is fired with an error. Previously, it was exiting with 0 in case of both success and fail.

Also, notice that the callback-less usage of facades is limited to cli. Grunt wrapper and possible future implementations are able to provide the optional callbacks and do different things in case of errors.