(5 kyu) Fibonacci Generator.md

Fibonacci Generator (5 kyu)

https://www.codewars.com/kata/522498c9906b0cfcb40001fc

Create a function generator genfib() that returns a function fib() which always returns the next fibonacci number on each invocation (and returns 0 when being called the first time).

Example:

var fib = genfib();
fib(); // -> returns 0
fib(); // -> returns 1
fib(); // -> returns 1
fib(); // -> returns 2