Feature/reversing distribution

Reversing distribution to patient and to service
The javascript keyword `delete` is slow, especially in a loop.  Since the delete operator does not free up memory, it is often better to set `object.property = null;` instead.

Additionally, you are objects within a forEach loop!  Array.forEach() does not assume you are changing the array elements, this could would be better implimented using Array.map(), so that you only return the properties you need.  That way, you don't use delete at all.