commit => elixir_fibonacci.exs , ruby_fibonacci_recursive.rb

[Bindles]

I wrote it in elixir as [elixir_fibonacci.exs] and i also wrote a recursive version in ruby since i noticed in c++ you have both iterative/recursive versions. the recursive ruby function is extremely simple , concise, uses memoization and guaranteed to be very fast. Thank you for the opportunity to contribute.
-Nicholas Turner