KAZOO-2560 - CAMP-ON feature

Does this actually work??? It looks like an arity-3 macro. Should it not be:

````
-define(MK_CALL_BINDING(CallId), [{'callid', CallId}, {'restrict_to', [<<"*">>]}]).
````

I'm genuinely surprised your macro works as expected. I guess the compiler reads from the `,` and to `).` to do the replacement?