Translated to Elixir.

Added Elixir implementation!

Thanks. I forked it and made the update there, since I couldn't just update it and save.

Elixir translation added for approval.

Could you please include Elm on the list of languages?

Could you please update the Elixir interpreter to 1.5?

Added in some concurrency when finding the prime factors... seems to help scale that portion. I will add it to the prime? section soon.

I know mine looks convoluted, and I will update more later, but I wanted to trim down to the heart of the loop, which is consistent across both prime? and count_prime_factors/3. Although verbose, this should do less work. I want to also cut a lot of this list creation down into lazy streams...