So I realized that even though I'm just getting started, I'm already behind. chuckle. Here you go:

elixir --version
Erlang/OTP 18 [erts-7.3] [source] [64-bit] [smp:4:4] [async-threads:10] [hipe] [kernel-poll:false] [dtrace]

Elixir 1.2.4

So it is the normal brew process (you type what's in bold):

**brew update**
  
**brew upgrade elixir**
  
elixir --version
  
elixir --version
Erlang/OTP 19 [erts-8.0.2] [source] [64-bit] [smp:4:4] [async-threads:10] [hipe] [kernel-poll:false] [dtrace]

Elixir 1.3.2