Function Prototype: harmonic_recursive(n)
Function Parameters: n - the nth Harmonic number

Function Description: Calculate the nth Harmonic number recursively.

Implementaion details:

Base case: if n == 1: return 1

Recur step: If not the base case, call harmonic_recursive for n-1 and add the
            the result with 1/n, that is return 1/n + harmonic_recursive(n-1)

Pseudocode:

harmonic_recursive(n):
    if n == 1:
        return 1
    else:
        return 1/n + harmonic_recursive(n-1)

