I am also a Ruby/Rails developer. It is a great framework but I wanted to try something new for my side project so I started learning Elixir/Phoenix.
I have now deployed two applications using Elixir. One is a simple blog and the other is the side-project that I am currently working on called Email This [1]. Overall, I've been very happy with Elixir. The learning curve is not too steep and the docs are very exhaustive.
For my next project, I am planning on trying Go. There were many great resources shared in this post on HN today [2].